Capture of Arendal The Capture of Arendal occurred on 9 April 1940 and saw the German torpedo boat " Greif " land a force of bicycle troops and seize an invasion beachhead at the Norwegian port town of Arendal . The main aim of the landing , part of the German invasion of Norway , was to sever the undersea telegraph cable between Arendal and the United Kingdom . The German force landed unopposed , with the Norwegian torpedo boat based in the town choosing to evacuate rather than take up the fight against the surprising arrival of the Germans . The Norwegian naval commander cited concern for civilian casualties and a glum view of his chances as reasons for not resisting . While the initial German occupation of Arendal took place without serious incident , panic broke out the following day and led to many civilians abandoning the town , following unfounded rumours of an incoming British bomber raid . Five days after the German occupation of Arendal , the town saw the establishment of the first organized resistance group in Norway . The Arendal Group operated from 14 April 1940 until crushed by the Gestapo four months later . Background . After the outbreak of the Second World War in September 1939 , Norway declared her neutrality in the conflict . During the following months Norwegian neutrality was repeatedly ignored and violated by both the Axis and the Allies . On the part of the Germans , the violations included U - boat attacks on both Allied and neutral shipping within Norwegian territorial waters . The Norwegian Armed Forces were ill - equipped , poorly trained , only partially mobilized , and unable to efficiently defend Norwegian territory against neutrality violations . On 16 February 1940 , the British Royal Navy breached Norwegian neutrality in an operation to rescue 299 captive British sailors from the German auxiliary " Altmark " in the Norwegian Jøssingfjorden . Norwegian naval vessels observed the British operation , but did not intervene . Angered by the Altmark Incident , Adolf Hitler the next day ordered the invasion of Norway . Among Hitler ' s stated reasons for invading Norway was a need to pre - empt a potential British landing in Norway , a desire to secure the iron ore and other natural resources originating in or being supplied through Norway , and to secure Germany ' s northern flank while giving the Kriegsmarine easier access to the Atlantic Ocean . Hitler ' s concern about potential British landings in Norway was encouraged by Norwegian fascist leader Vidkun Quisling , who claimed that an alliance between the United Kingdom and Norway ' s Labour Party government was in the making . General Nikolaus von Falkenhorst was given overall command of the invasion of Norway . Prelude . In the plans for an attack on Norway presented on 29 February 1940 to Hitler by General von Falkenhorst , Arendal was one of the Norwegian towns and cities to be captured in the initial invasion wave . Like the port town of Egersund , which was also to be seized , Arendal had a land station for one of the two undersea telegraph cables between Norway and the United Kingdom . The Germans set out to cut the cable to the United Kingdom , as well as securing the telegraph cables to Denmark and Cuxhaven in Germany . Arendal was also important as a telegraph junction for the southern parts of Norway , with German personnel tasked to listen in on Norwegian communications . Isolating Norway from the outside world was an important part of the German effort at pacifying the Norwegian population and discouraging resistance to the occupation . The task of seizing Arendal fell on " Gruppe 4 " of the German invasion fleet . The primary objective of " Gruppe 4 " was the capture of the main port in Southern Norway , Kristiansand . A single torpedo boat , " Greif " , was detached from the task force on 8 April , " Gruppe 4 " having left Wesermünde in Germany at 05 : 00 the same day . Before proceeding on her own , " Greif " had been escorting the E - boat tender " Tsingtau " off the west coast of Denmark . In Arendal there was much tension due to the sinking of the German transport " Rio de Janeiro " off the nearby port of Lillesand that day . " Rio de Janeiro " , a covert troopship en route to Bergen with 313 " Luftwaffe " personnel and anti - aircraft guns , had been intercepted and torpedoed off Lillesand by the Polish submarine " Orzeł " . Some of the German survivors told Norwegian police officers that they had been on their way to Bergen to " help the Norwegian government protect the country ' s neutrality " . Twelve wounded Germans were admitted for treatment at Arendal and Aust - Agder Hospital in Arendal . The regional newspaper " Agderposten " , based in Arendal , ran an extra edition on the " Rio de Janeiro " sinking and reports of German fleet movements off Southern Norway . Opposing forces . German . The German force tasked with the capture and occupation of Arendal was the 90 - strong 234th Bicycle Squadron of the 163rd Infantry Division , commanded by " Rittmeister " Smith von Wesentahl , with an attached unit of ten signals personnel . The signals personnel were to operate the town ' s telegraph station and sever the telegraph cable to the United Kingdom . Transporting the landing force to Arendal , and providing support in case of Norwegian resistance , was the Raubvogel class torpedo boat " Greif " , commanded by " Kapitänleutnant " Wilhelm - Nikolaus Freiherr von Lyncker and carrying torpedo boat flotilla commander " Korvettenkapitän " Wolf Henne . Once the army troops were on shore and in control of the town , " Greif " was to sail off and rejoin the rest of " Gruppe 4 " at Kristiansand . The Germans did not expect resistance at Arendal , the town being unfortified and without a garrison . Norwegian . The sole Norwegian military unit in Arendal was the 75 - ton 2 . class torpedo boat , commanded by Lieutenant Thore Holthe . Following reports of German ships off Denmark and at the entrance to the Oslofjord , Lieutenant Holthe had put his 18 - man crew on increased readiness and brought up ammunition for the vessel ' s 37 mm guns and 7 . 92 mm machine gun . In accordance with Norwegian mobilization plans a company of infantry was supposed to be set up to defend Arendal . However , no mobilization orders had been issued prior to the German attack , so the town lay undefended on the landward side . Landing . As " Greif " made her way towards Arendal , the torpedo boat encountered thick fog , forcing " Kapitänleutnant " von Lyncker to decrease the vessel ' s speed , delaying the arrival at Arendal . According to the operational plans for the invasion , all the German landing groups were to arrive at their targets simultaneously at 04 : 15 . " Greif " arrived at Arendal at 08 : 20 . At 01 : 00 , still more than seven hours from their objective , the Germans had received radio reports of fighting taking place in the Oslofjord . All the lighthouses along the southern Norwegian coast , from Marstein Lighthouse in the west to the Swedish border in the east had been turned off the previous evening , on the orders of Commanding Admiral Henry Diesen of the Royal Norwegian Navy . Although spotted by customs personnel as she made her way through the narrows leading to the town , the reports of the intruding warship did not reach Lieutenant Holthe on board " Jo " . As " Greif " entered the harbour in Arendal at 08 : 30 , she was spotted from " Jo " . At the time , " Jo " had been about to set off for Lyngør to join the fellow torpedo boats and in order to operate as a group . Norwegian neutrality rules regulated that since Arendal was not a protected war port , Lieutenant Holthe was required to have orders before opening fire at any intruder . As he had no orders or information to act on , and " Jo " was in an unfavourable position to attack , the torpedo tubes of the moored naval vessel pointing inland , Lieutenant Holthe refrained from opening fire . " Greif " reached the quay without encountering any resistance other than a few rifle rounds fired by a customs officer and his son . The 100 - strong landing force quickly disembarked and occupied the town . By 09 : 00 , " Greif " set off for Kristiansand . During the short time " Greif " spent in Arendal , Lieutenant Holthe on " Jo " considered carrying out an attack , but avoided engaging due to the fire power of the German warship , and the numerous civilian onlookers crowding the quay area . As " Greif " was about to depart Arendal , a Norwegian Marinens Flyvebaatfabrikk M . F . 11 seaplane ( F . 328 ) landed in the harbour next to the German torpedo boat . The Norwegian seaplane was one of four that had escaped from Kristiansand before the German attack on that city . Before the Germans reacted to the M . F . 11 , the Norwegian aircrew realised that Arendal had been captured , and took off . Chased by anti - aircraft fire , the M . F . 11 flew south to the nearby unoccupied village of Fevik . The bicycle - mounted German infantry seized control of the town ' s railway station , post office , police station and telegraph building . The undersea cable to the United Kingdom , which unbeknownst to the Germans had been inoperable for more than three months , was severed . As they took control of the town without encountering any opposition , the Germans also seized a cache of rifles which had been used by the Norwegian authorities to provide military training to civilian volunteers in the months prior to the invasion . Before the Germans reached the Norwegian Army ' s air raid station and the Royal Norwegian Navy ' s group central in Arendal , the administrative officers there had made their way out of the town . Aftermath . After " Greif " had left Arendal , Lieutenant Holthe took " Jo " out of the harbour and set up an ambush east of the town in case the German warship came back in that direction . Some time later on 9 April , " Jo " steamed to Lyngør where she met up with " Grib " and " Ravn " . The three torpedo boats spent the next eight days trying to support the Norwegian land forces being mobilized in Telemark county , surviving several air attacks during the time . After considering evacuating the torpedo boats to the United Kingdom , and dismissing the idea as infeasible , Lieutenant Holthe and the other commanders scuttled their vessels off Lyngør on 17 April . The crews went home and the ship commanders tried to join Norwegian forces in Western Norway . Although the population of Arendal had reacted calmly to the German invasion , rumours soon began to circulate about a supposed Allied bombing raid scheduled for 12 : 00 on 10 April . Most of Arendal ' s population fled the town in panic in the early hours of 10 April . It took several days before the majority of the evacuees had returned . The German landing force were housed in a school building , and " Rittmeister " von Wesentahl arranged meetings with the local Norwegian authorities to ensure their cooperation in accordance with the rules of occupation . Arendal ' s mayor agreed to help maintain calm in the town . On 14 April , five days after the German invasion of Norway and the bloodless conquest of their town , a number of Arendal ' s citizens founded the Arendal Group . The Arendal Group is generally regarded as the first organized resistance group in occupied Norway during the Second World War . The group , mostly men employed in the shipping industry , initially functioned to provide supplies to the Norwegian forces fighting at Vinje in Telemark . After the fighting at Vinje ended on 5 May , the group continued their activities with intelligence work until discovered by the Gestapo on 14 August 1940 . Close to 100 people were arrested in connection with the Arendal Group .