Early on April 9, 1940, at the Oscarsborg fortress in the Drøbak Narrows of the Oslofjord, the soldier on duty at the main guard post wrote a line in the guard log: At 4.25 a German warship suddenly appeared. Fire was opened from both sides.

Beside it he added a small heading: The warship versus the fortress. The next entry read: The warship has been set on fire and lies off the north islet.

The handwriting is clear and steady. But across these pages spreads a large ink stain, and tiny splinters of glass are caught in the binding. The National Archives of Norway, which holds the log, suggests that the guns knocked over the inkwell in the guard hut and shattered its windows.

The log caught only one small corner of that morning. At the same moment, some men stood on the bridge of a German cruiser, some sat in a conference room at the Foreign Office in Oslo, and some waited by a telephone in a newspaper agency's air-raid shelter. Each saw only a piece, and what they later wrote down did not agree.

I. A Fleet in the Fog

At 23.10 on April 8, the Norwegian patrol boat Pol III reported from Færder at the mouth of the fjord that foreign warships were forcing their way in.

According to the official Norwegian overview of the fighting written for the postwar investigating commission, the squadron passed between the outer batteries of Rauøy and Bolærne at 15 knots. Bolærne caught only a glimpse and never got off a shot. Rauøy fired a warning shot at 23.32 and three minutes later opened fire on the leading and largest ship. It fired four rounds and scored one hit before the silhouettes vanished into the fog. The Germans did not reply.

The fog thickened. The squadron held its formation, with the heavy cruiser Blücher in the lead. Small craft came alongside the cruisers, took off landing troops and split away toward the naval base at Horten and the outer forts.

Blücher was the newest heavy cruiser in the German navy. On this voyage she carried, besides her crew, more than 800 army troops and 31 tons of supplies. Her bridge was crowded: Rear Admiral Oskar Kummetz, who commanded the group; Major General Erwin Engelbrecht of the 163rd Infantry Division; their staffs; and most of the senior officers of her captain, Captain Heinrich Woldag. The radar worked perfectly well, but once inside the fjord Woldag switched it off, because echoes from the mountains on both shores made it useless.

II. A Timetable

The squadron was racing a deadline.

The German plan fixed a moment called "Weser time" at 4.15. That was not the hour the warships would enter Norwegian waters, but the hour they were meant to be lying off the main cities. Five minutes later, at 4.20, the German minister in Oslo, Bräuer, was to call on the Norwegian government and urge it to order that no shots be fired. Falkenhorst's staff saw the weakness and tried to move the diplomatic step earlier. Hitler refused, fearing that early warning would send Norway to ask Britain and America for help.

Bräuer's instructions contained one more point: it was especially important to prevent the King of Norway from leaving the country during the occupation, and if necessary to watch the palace directly and stop him from leaving it.

An appendix published by the Norwegian investigating commission in 1947 records a detail: Blücher carried a military band, which was to march between four and five in the morning from the harbor to the Palace Square and play a march of homage to the King.

Schreiber, the German naval attaché in Norway, had orders to be at Oslo harbor at four to receive the ship. He told the commission after the war that he had worried in advance that the Norwegians would open fire as the squadron came through and wreck the whole plan. He cabled the naval high command and suggested that the ships signal, as they passed Oscarsborg, that they came in with the Norwegian government's consent and had a Norwegian officer on board.

Aboard, things looked different. The Canadian scholar Peter Mispelkamp, drawing on reports in the German naval files, wrote that Kummetz was under orders to bluff his way in, and that he told his ships to ignore warning shots, ranging shots and searchlights. On the eve of the invasion the Germans had cabled the Krupp company's representative in Norway for information on the Norwegian coastal batteries, and his hasty report left out the three old Krupp 280mm guns at Oscarsborg. To keep the secret, practice rounds were never unloaded, and live shells were simply stacked on top of them. Army ammunition was stowed everywhere, even in the nearly unprotected aircraft hangar. Nor were extra life jackets issued for all the additional men; only about 200 inflatable vests were loaded for the engine-room staff.

III. The Old Fortress

Oscarsborg was manned at only part of its strength. The official overview lists what was crewed that night: the three 28cm guns of the main battery on Kaholmen, three 15cm guns at Kopås on the eastern shore, a few 57mm guns at Husvik and Nesset, two 40mm anti-aircraft guns and some machine guns, and two patrol boats. The torpedo battery had been made ready. Not one mine had been laid in the Drøbak Narrows: on the evening of the 8th, the order was to call in the mine personnel at once, but to lay no mines without further orders.

The fortress commander was Colonel Birger Eriksen. The old guns of the main battery loaded slowly; after each round there was a long wait before the next.

He had in hand the navy's general instruction for neutrality watch of August 29, 1939. As the writer Morten Svinndal quotes it, the instruction said that force was not to be used without orders from the Commanding Admiral, unless one was attacked; but ships that, despite protest, tried to force their way into a naval harbor or the defended area of a coastal fortress were to be stopped with all available means.

By now he knew that the outer forts at Rauøy and Bolærne had fired warning shots. At 3.38, Filtvet reported that the foreign warships were steaming north with their lights out.

IV. Four Minutes

Day was breaking. German clocks ran an hour ahead of Norwegian ones: Germany had gone onto summer time on April 1; Norway had not.

According to the official overview, the squadron entered the channel to Drøbak at 9 knots, 600 meters between ships, and slowed to about 6 knots inside the narrows. Blücher slid into the beam of a searchlight on the Drøbak side; four minutes later both shores opened fire. The German report Mispelkamp used says instead that a searchlight had caught her again more than forty minutes before the guns spoke.

By Norwegian time it was 4.21. The two 28cm guns of the main battery each fired one round at about 1,400 meters. The official overview says both struck well, the first into a compartment holding bombs, with violent effect. The 15cm guns at Kopås joined in at once.

The German record sees the moment from the ship. One heavy shell destroyed the main anti-aircraft control platform. Another tore into the hangar, and a sea of flame engulfed the ship's floatplane and wrecked a 105mm mount to port. A third damaged the engine telegraphs and jammed the rudder to port. The battery at Kopås fired twenty-five salvos and scored twenty hits, and communications aboard were all but cut.

Blücher's main-gun crews could find nothing to aim at; her light and medium anti-aircraft guns fired at anything that looked like a target. Woldag ordered fire to be opened, rang for full speed, and ordered counter-steering to keep her off the rocks of North Kaholmen.

Then came two dull blows from under the water. At first the officers thought they had strayed into a minefield. Damage-control parties soon found the truth: torpedoes.

Hidden in the rock of North Kaholmen was a torpedo battery. According to a later article in the German newspaper Die Welt, its regular commander was on sick leave and a long-retired officer named Andreas Anderssen had stepped in; the torpedoes he fired were forty years old.

V. Turning Back

Shortly after 5.30 German time, making about 15 knots and listing 8 to 12 degrees, Blücher cleared the batteries' fields of fire. Kummetz handed command of the squadron to Captain August Thiele of the Lützow behind her.

The guns turned on the ships that followed. One of Lützow's main turrets was soon silenced. Thiele ordered the whole squadron to turn back and put the troops ashore farther south, avoiding the narrows. He also countermanded every order to help the flagship, judging that a rescue attempt would only cost more lives.

The ships that turned back lay to near Jeløya. The troops were later landed at Moss, Son and other points and pushed toward Oslo by road on motorcycles, in armored cars and trucks.

VI. At Anchor

Once clear of the guns, Woldag thought only of saving his ship.

Even as the engines failed one after another he stayed hopeful. He ordered the anchors dropped to keep her from drifting aground while the engineers tried to restart the turbines, and sent his executive officer, Commander Erich Heyemann, to survey the damage. Heyemann found a ship on fire. The hangar blaze had spread and set off the army munitions stored nearby, cutting the ship in two so that neither half could help the other. Forward, the port side was torn open and pouring smoke. Most of the fire hoses had been shredded by splinters. All over the ship, men gathered in makeshift parties to throw ammunition overboard and flood the magazines.

At a list of 18 degrees Woldag still believed she could be saved. Only when the fire reached the amidships 105mm magazine and it blew up did he change his mind. The one boat still usable was lowered for the wounded. At 7.00 German time the list reached 45 degrees and he ordered the crew to abandon ship.

At about 6.20 Norwegian time, Blücher rolled over near the Askholmene islets and went down.

The men in the water swam for the islets and the shore. On its second trip the boat was badly damaged, and those still in the water had to swim. Mispelkamp writes that many sailors gave their life jackets to soldiers who could not swim, and that others refused. The men on the islet waited until the evening of that day and later before anyone came for them.

VII. Morning in Oslo

C. J. Hambro, President of the Storting, spent the night on the telephone. He later wrote that around two o'clock the staff of the news agency came up from their shelter to take his call and told him that foreign warships had passed Færder at midnight, heading up the fjord. At half past three he learned that the German squadron was fighting at Oscarsborg.

He concluded that the Germans would be in the city before the day was out. He had the Clerk of the Storting pack the archives, the minutes and the seals and order trucks, and then went to the Foreign Office, where the Cabinet was in session.

Between 4.30 and 5.00, the German minister, Bräuer, called on Foreign Minister Halvdan Koht and handed him a memorandum with a long list of demands that, in Hambro's words, amounted to a complete surrender. Bräuer said there was no time to lose: the German navy had orders to occupy the towns before nine, or ten at the latest. The government refused at once.

Hambro proposed that the King, the Cabinet and the Storting move inland to Hamar. A special train was set for seven o'clock from the Eastern Station. It ran late. At Lillestrøm the nearby Kjeller airfield was being bombed; the train stopped for a while, and the royal family and other passengers sheltered in the underground passages between the platforms. When the roll was called at Hamar that afternoon, 146 of the 150 members were present. The Storting was also told that the gold of the Bank of Norway had been safely taken out of Oslo.

On the German side, Lieutenant Colonel Pohlmann of Falkenhorst's staff, sent ahead to Oslo, cabled headquarters at 6.18 Norwegian time: No ship to be seen off Oslo, no sound of fighting. Air-raid alarm, crowds in the streets. The Norwegian government declares: "We will not submit; the fight has already begun."

Schreiber waited on the docks until about nine before he understood that something had gone badly wrong. He went back to the legation and had the staff take up arms. When he ventured out again later that day, he wore a civilian coat over his uniform.

Around nine that morning German airborne troops landed at Fornebu airfield, and Oslo was occupied the same day. In his notes for the war diary at the German High Command, Major Deyhle wrote that since the Norwegian government could not be taken by surprise, Norway had to be occupied by force.

VIII. Accounts That Do Not Match

That night and morning left several records, and they do not agree.

Hambro's book appeared in 1940, while the war was still on. He wrote that the biggest German ship, the 26,000-ton Gneisenau, was struck by two torpedoes in the narrows, her oil tanks exploding, with some 3,000 men reportedly aboard; and that the 10,000-ton Blücher was sunk by the fortress guns, with 1,600 reportedly aboard. But there was no Gneisenau in the German group that entered the Oslofjord. Blücher was the only ship torpedoed and sunk in the narrows. Hambro was on the road all that day; what he wrote down was most likely the news as it reached Hamar.

The official overview published in 1947 says that a small German ship, the Brummer, was hit so badly that she sank off Drøbak, and that a good half of the roughly 2,000 men aboard Blücher died. Mispelkamp cites an unofficial estimate that about 1,600 of more than 2,100 aboard were lost, and notes that this is the only source that gives an estimate of the number of men lost. A 2023 article in the German newspaper Die Welt gives a range from the roughly 320 bodies officially recovered to about 1,000.

The clocks do not agree either. The guard log says 4.25. The German reports have the searchlight catching the flagship again at 4.40 and the guns opening forty-one minutes later, at 5.21, which is 4.21 Norwegian time. The extra hour is the difference between the two countries' clocks. In a single paragraph, the 1947 overview gives 5.17 and 5.21 for the opening of fire, which match German time, and 6.20 for the sinking, which is Norwegian time.

And there is the famous remark. What Eriksen said before he gave the order to fire survives in more than one version. In one, he says: "Of course, damn it, we'll fire live rounds!" In another, which a 2015 report by the Norwegian broadcaster NRK says he "is said to have" spoken: "Either I'll be court-martialed or I'll be a war hero. Fire!" He wrote his own report on August 5, 1940; this article could not read the original.

Every one of these records comes from someone who saw only a corner. The men on the ship saw fire, the men at the fort saw a silhouette, the President of the Storting heard a telephone, and the attaché looked at an empty harbor.

Epilogue

After Blücher went down, Oscarsborg was bombed through the whole day. That evening German troops took the batteries on the eastern shore from the landward side.

The last entry in the guard log reads: The guard was withdrawn at 10.15 on the orders of Colonel Eriksen, as the Germans were to take over the guard.

That same morning, April 10, the rest of the German squadron passed through the narrows and entered Oslo.

Where the log went after that, no one can say. Only in 2003 was it transferred to the National Archives from the Labour Movement Archives, where it had lain since the 1970s among the papers of the hairdressers' union. Whether a soldier who had stood guard that night took it with him and later became a barber, or whether it took some other road, the archives do not know.

The ink stain is still on the page.

Sources and Editorial Boundaries

1. Guard log of the Oscarsborg main guard, April 9, 1940 (Vaktjournalen fra Oscarsborg 9. april 1940), held by the National Archives of Norway; used from the archive's web presentation and the wording it quotes: https://www.nasjonalarkivet.no/vaktjournalen-fra-oscarsborg-9-april-1940/ . Used: "At 4.25 a German warship suddenly appeared. Fire was opened from both sides," with the side note "The warship versus the fortress"; "The warship has been set on fire and lies off the north islet"; the clear, steady hand, the large ink stain and glass splinters in the binding, and the archive's inference that the inkwell was knocked over and the windows shattered; the air attacks on April 9; the last entry, "The guard was withdrawn at 10.15 on the orders of Colonel Eriksen, as the Germans were to take over the guard"; transfer in 2003 from the Labour Movement Archives (Arbeiderbevegelsens arkiv), where it had lain since the 1970s among the papers of the hairdressers' union, route unknown. The original was not seen; only the archive's quoted wording is used.

2. Official Norwegian overview: J. H. Nordlie, "Kort oversikt over kampene i Norge våren 1940," appendix no. 2 in Innstilling fra Undersøkelseskommisjonen av 1945, Bilag, vol. 1 (Oslo: Aschehoug, 1947), pp. 90–91, 103–105, read page by page in the Internet Archive scan: https://archive.org/details/InstillingUnderskelsesKommisjonen1945Bilag1 . Used: Pol III's report from Færder at 23.10; the squadron passing Rauøy and Bolærne at 15 knots, Bolærne unable to fire; Rauøy's warning shot at 23.32 and fire at 23.35, four rounds, one hit; no German reply; worsening visibility and the transfer of landing troops to small craft, detachments for Horten; 9 knots, 600 m between ships, about 6 knots in the narrows; Blücher entering a searchlight beam from the Drøbak side at 5.17 and fire opened from both shores four minutes later; fire aboard, fire control and steering destroyed, two torpedoes; sinking at 6.20 near Askholmene with "a good half" of about 2,000 aboard dead; the two slow-loading 28cm guns each firing one round at 1,400 m, both hitting, the first in a "bomberom"; Kopås following at once; the Brummer sinking; the retreating ships lying to at Jeløya; the eastern batteries taken from landward in the evening by troops landed at Son; the rest of the squadron entering Oslo the next morning, when the city had already been occupied by airborne troops who had landed at Fornebu around nine in the morning (p. 105: "som landet på Fornebu ved 9-tiden om morgenen"). Pp. 90–91: the fortress at reduced strength and the batteries actually manned (Kaholmen 3 × 28cm, Kopås 3 × 15cm, 57mm guns at Husvik and Nesset, 2 × 40mm AA and machine guns, 2 patrol boats), torpedo battery ready; no minefield laid anywhere on April 8. P. 103: the order on the evening of April 8 to call in Oscarsborg's mine personnel at once but lay no mines without further orders.

3. Same volume, appendix no. 1: Helge Sivertsen, "Tysklands planer om overfall på Norge," pp. 24–26 (same scan). Used: "Weser time" at 4.15 as the hour the ships should lie before their targets, the diplomatic step at 4.20; Falkenhorst's staff seeking to advance it and Hitler's refusal for fear Norway would appeal to Britain and America (Sivertsen cites Jodl's diary); the instruction to Bräuer to prevent the King from leaving the country and if necessary to watch the palace; the military band aboard Blücher, due to march between four and five from the harbor to the Palace Square and play a march of homage (Sivertsen cites an annex to Bräuer's instructions, not seen); naval attaché Schreiber's statement to the commission dated May 5, 1946 (orders to be at Oslo harbor at four, his fear of Norwegian fire, his cable proposing a signal claiming Norwegian consent and a Norwegian officer aboard); the 6.18 message (marked "Norwegian time") from Lieutenant Colonel Pohlmann of Falkenhorst's staff, who had carried Bräuer's instructions to Oslo (p. 24 note); Major Deyhle's notes for the OKW war diary. The German originals were not seen; all are quoted from Sivertsen.

4. The German shipboard account: Peter K. H. Mispelkamp, "Avoidable Loss: The Saga of the Blücher," The Northern Mariner / Le marin du nord 6, no. 3 (1996): 25–38, full text: https://www.cnrs-scrn.org/northern_mariner/vol06/tnm_6_3_25-38.pdf . The author bases the shipboard narrative chiefly on the report of the executive officer, Fregattenkapitän Erich Heyemann (PG 47900), and that of Oberleutnant zur See Freiherr von Freyberg (PG 47902), in the Blücher battle-and-loss file, US National Archives microfilm T-1022; these reports were not read here and are used at second hand. Used: Blücher as the newest heavy cruiser; over 800 troops and 31 tons of supplies; practice rounds left aboard with live rounds on top; army munitions stowed even in the hangar; no extra life jackets, about 200 inflatable vests for the engineers; Kummetz, Engelbrecht, staffs and senior officers on the bridge; radar switched off in the fjord; orders to bluff in and to ignore warning shots, ranging shots and searchlights; the Krupp representative's report omitting Oscarsborg's 280mm guns; searchlights again on Blücher at 04.40 German time and the main guns opening 41 minutes later; three 280mm hits (main flak-control platform; hangar, floatplane on fire, port 105mm mount III destroyed; engine telegraphs, rudder jammed to port); twenty hits from twenty-five salvos by the 150mm battery, communications crippled; main gunners without targets and wild anti-aircraft fire; Woldag's orders to open fire, full speed and counter-steering off North Kaholmen; two underwater explosions first taken for mines, then found to be torpedoes; clearing the arcs shortly after 05.30 at about 15 knots with an 8–12° list; command passed to Thiele of Lützow; one of Lützow's turrets silenced; Thiele's retreat, landing farther south, and countermanding of aid to the flagship; anchoring, Heyemann's damage survey, the hangar fire and army munitions dividing the ship, the torn port side, hoses riddled with splinters, makeshift parties dumping munitions and flooding magazines; hope at 18°, the amidships 105mm magazine explosion, the one usable cutter, 45° and abandon ship at 07.00, capsizing at 07.23 (all German time); mixed conduct over life jackets; the cutter damaged on its second trip; survivors waiting until the evening of April 9 and after; Schreiber on the docks until about 09.00, arming the legation, the civilian coat; the unofficial estimate of about 1,600 lost out of over 2,100 (from Manchester, The Arms of Krupp, p. 460; Mispelkamp's note 28: "this is the only source that gives an estimate of the number of men lost"); the opening of fire: the searchlight caught the flagship again at 4.40 German time and the guns fired 41 minutes later, i.e. 5.21 German, 4.21 Norwegian (this article's conversion). The composition of Group V (Blücher, Lützow, Emden, three torpedo boats, two flotillas of auxiliaries) is also from this article.

5. Oslo: C. J. Hambro, I Saw It Happen in Norway (New York: D. Appleton-Century, 1940; London: Hodder and Stoughton, 1940), Internet Archive scan of the Digital Library of India copy: https://archive.org/details/in.ernet.dli.2015.536852 , pp. 11–24, 183–188. Used: the news agency staff answering from their shelter around two, warships past Færder at midnight; news at 3.30 of fighting at Oscarsborg; packing of the Storting's archives, minutes and seals, trucks ordered; the Cabinet in session at the Foreign Office; Bräuer's memorandum to Koht between 4.30 and 5.00, demands amounting to complete surrender; Bräuer's statement that the navy was to occupy the towns before nine or at the latest ten; immediate refusal; the move to Hamar, the special train for seven from the Eastern Station, its late running, the stop at Lillestrøm as Kjeller was bombed, shelter in the underground passages; 146 of 150 members at the afternoon roll call; the report that the Bank of Norway's gold had been taken out of Oslo; his account of the Gneisenau (26,000 tons, two torpedoes, oil tanks exploding, some 3,000 reportedly aboard) and of Blücher (10,000 tons, sunk by the fortress guns, 1,600 reportedly aboard); German landings at Moss and Filtvet and the advance by motorcycle, armored car and truck.

6. The neutrality instruction: The wording of the navy's general neutrality instruction of August 29, 1939, Filtvet's 03.38 report, the darkened ships, and Eriksen's knowledge of the warning shots at Rauøy and Bolærne: Morten Svinndal (author of the book Kommandanten), "Oberst Eriksen fulgte faktisk instruksen," a signed opinion piece (not a news report), Forsvarets forum, February 20, 2026 (the publisher, year and pages of his book Kommandanten have not been checked): https://www.forsvaretsforum.no/andre-verdenskrig-historie-krigshistorie/oberst-eriksen-fulgte-faktisk-instruksen/484889 ; the instruction itself was not seen. Svinndal names Eriksen's report of August 5, 1940, the fortress signals log and Rear Admiral Smith-Johannesen's report as the documentary basis; none of the three was read here.

7. The torpedo battery: its regular commander on sick leave, the retired Anderssen in temporary command, and the forty-year-old torpedoes, from Johann Althaus in Die Welt, April 11, 2023 (https://www.welt.de/geschichte/zweiter-weltkrieg/article244668176/ ), which is also the source for the range from about 320 recovered bodies to about 1,000 dead. This is a newspaper article, not a primary source; the text attributes these details to Die Welt and takes only the barest facts. The corresponding passage in Jacobsen's Krysseren Blücher (2010) has not been checked.

8. Time zones: on April 9, 1940, Germany had been on summer time (UTC+2) since April 1, while Norway kept Central European standard time (UTC+1), per the IANA time zone database entries for Europe/Berlin and Europe/Oslo and the 1940 German decree introducing summer time (Reichsgesetzblatt; volume and page not yet checked). German times run one hour ahead of Norwegian.

9. Boundaries. (1) The time fire was opened: 4.25 in the guard log, in Mispelkamp's German reports the searchlight caught the flagship again at 4.40 German time and fire opened 41 minutes later, i.e. 5.21 German, 4.21 Norwegian (the conversion is this article's). Nordlie's paragraph gives 5.17 and 5.21 for the opening, matching German time, and 6.20 for the sinking, Norwegian time; that he mixed the two clocks is this article's inference. (2) Main-battery hits: two of two in Nordlie, three in Mispelkamp's German sources; both are given. (3) The searchlight: four minutes before fire in Nordlie, 41 minutes before ("again") in Mispelkamp; not resolved. (4) Outer forts: Nordlie gives Rauøy's warning shot at 23.32 and fire at 23.35; Hambro, from what he heard by telephone, says 12.45; Nordlie is followed. (5) The Lützow turret silenced: forward in Mispelkamp; later accounts differ and have not been checked here; the text says only "one of her main turrets." (6) Deaths: "a good half" of about 2,000 (Nordlie); about 1,600 of over 2,100 (unofficial estimate in Mispelkamp); about 320 bodies to about 1,000 (Die Welt, a newspaper). All are given, none is chosen. (7) The Brummer: Nordlie (published 1947) has her sunk off Drøbak. Later accounts differ; they have not been checked here, so the text gives only Nordlie's version, in the section on conflicting records. (8) Hambro's Gneisenau does not fit the composition of Group V, which the text points out on Mispelkamp's evidence; that he wrote down news as it reached Hamar is this article's surmise and is marked as such. His reports of the Drøbak rector hearing screams and of hundreds of bodies floating to Oslo are hearsay and are not used. (9) Eriksen's remark: "Visst Fanden skal der skytes med skarpt!" is from Alf R. Jacobsen, Krysseren Blücher (Oslo: Vega, 2010), as quoted in a Dagbladet review by Arne Dvergsdal (online June 11, 2010; print April 26, 2010); the book itself has not been checked. "Enten blir jeg stilt for krigsrett, eller så blir jeg krigshelt. Fyr!" is in an NRK report of April 9, 2015 (Kirsti Haga Honningsøy and others, "Det var motstand mot å angripe Blücher," https://www.nrk.no/norge/_-det-var-motstand-mot-a-angripe-blucher-1.12301159 ), which introduces it with "skal han ha sagt følgende" (he is said to have said) and gives no earlier source. Neither comes from Eriksen's own report. The sentences from that report quoted in Jacobsen's book ("The result was very surprising… Blücher seemed mortally hit") are known here only through the review and are not used. (10) The main point of the same NRK report is Jacobsen's view that Eriksen's senior officers did not unanimously support opening fire and that his personality forced the decision through. The report also says that Jacobsen holds that Anderssen asked for a written order before firing; Anderssen's great-grandson denies it, saying he asked over the line for a categorical order. The text leaves this out. (11) Eriksen's dates (1875–1958) are so far found only in reference works and have not been verified in primary sources or scholarly publications; the figure card marks them as unverified, and the text omits them. (12) The band is known only from Sivertsen's 1947 appendix (citing an annex to Bräuer's instructions); the annex was not seen. (13) Schreiber, Pohlmann and Deyhle are quoted from Sivertsen; the shipboard events from the German reports as summarized by Mispelkamp; none of the originals was read.

10. Key original wording: guard log "kl. 4.25 dukket plutselig et tysk krigsskib op. Det blev åpnet ild fra begge kanter." "(Krigsskibet kontra Festningen)" "Krigsskibet er skutt i brann, ligger utenfor nordholmen." "Vakten blev rømmet kl. 10.15 efter ordre fra oberst Eriksen da tyskerne skulle overta vakten." Neutrality instruction: "Det skal ikke brukes makt uten etter ordre fra Kommanderende admiral, eller hvis man blir angrepet. [...] Skip som tross protest søker å forsere inn til krigshavn eller kystfestningers forsvarsområde skal dog søkes stoppet med alle midler som står til rådighet." Instruction to Bräuer: "Særlig viktig er det at Kongen av Norge forhindres i å forlate landet ved okkupasjonen." Pohlmann: "Ikke noe skip å se foran Oslo, ingen kamplarm å høre. Flyalarm, menneskeansamling på gaten. Den norske regjering erklærer: «Vi bøyer oss ikke, kampen er allerede i gang.»" Nordlie: "Ilden fra Oscarsborg ble åpnet med at de 2 langsomtladende 28 cm kanoner skjøt hvert sitt skudd på 1400 m avstand. Begge skudd traff godt (det første i et bomberom) og hadde voldsom virkning." Hambro: "The German Navy had been ordered to occupy the various towns before nine o'clock, or, at the latest, ten o'clock in the morning." Mispelkamp: "At first, the officers surmised that the ship had strayed into a minefield, but damage control crews quickly determined that it had been torpedoed." Translations of Norwegian are the author's.

11. Rights: the commission's appendices are official publications; the guard log is quoted briefly from the archive's public page; Hambro's 1940 book, Mispelkamp's article, newspapers and web pages are used for facts and brief quotation only; the narrative is original.