Östfold is the southeast part of Norway. In this text it will refer to the area from Oslofjord to the Swedish border, south of a line from Oslo to Kongsvinger. This battle is seldom mentioned other than in passing, as it was a short action, and there were no British troops nearby. It was however an important battle, as a different outcome may have altered much of later events. In spite of its swiftness, it also contains a lot of different tactical and strategic opportunities for both sides.

The geography

To be able to describe the events for people without good maps, I will have to take some time describing the geography of the area.

Östfolds western border is the deep Oslofjord. At its most narrow part the old Oscarsborg coastal fortress is situated. Further south lies the town Moss, with a small port, and at the mouth of the fjord lies the more modern "Oslofjord" coastal fortress.

From the mouth of the Oslofjord there is a short, rather broken, coastline to the Swedish border. Here lies the cities Fredrikstad and Halden, and a few miles inland from Fredrikstad lies Sarpsborg. Fredrikstad is the most important city in Östfold. To the east Östfold borders to Sweden.

Östfold is divided in two approximately equal pieces by the big river Glåma, running from north to south with its mouth in Fredrikstad. It makes for a rather formidable river line with two long lakes covering about half its length, and from the southernmost lake the river forks in two and sometimes three branches past Sarpsborg and down to Fredrikstad.

The part of Östfold west of river Glåma is the denser populated region, with mixed terrain and a reasonably dense road net. East of the river most of the terrain is covered with dense forests, with few roads. Exceptions are a strip along the river and an area between the two long lakes where the river makes a bend to the west (approx. 20km long). At the area east of the river bend the terrain is quite open. There the small towns Askim and Mysen are situated. At the eastern end of this open area there is a fortress, "Fossumströket", built to defend the river-crossings at the river bend against attacks from the east.

The planned defence of Östfold

The first division under Gen. Erichsen was responsible for the defence of Östfold (district commander).

Two scenarios were contemplated when planning the defence; invasion over land through Sweden, or invasion over the sea.

A land invasion was supposed to be stopped at the Glåma river line, with the two most important crossings, at Sarpsborg and at Askim, was covered by forts.

An invasion over the sea was supposed to be stopped at the mouth of the Oslofjord by the Oslofjord coastal fortress. Thus the army units were supposed to defend the coast between the mouth of the fjord and the Swedish border. For this two local defence, and two field battalions, a bicycle squadron (company) and a light art. platoon (2x57mm guns) were scheduled. One local defence battalion, the artillery platoon and the bicycle squadron in the Fredrikstad area, one local defence battalion near Halden, while the field battalions should be stationed near Sarpsborg. A field brigade could be positioned further north.

Much emphasis was placed on the destruction of bridges in case of an invasion. Therefore each bridge had a civil "bridge commisar" and a "bridge guard", that in case of mobilization would gather at the bridge and prepare its destruction. Explosives and detonators were stored near the bridges.

The main defence installations within the area were:

- 1. Div HQ in Fredrikstad
- Infantry reg.1 (I.R.1) in Fredrikstad
- Artillery reg.1 (A.R.1) in Ski
- Fossumströkets festning - land fortress with two forts near Mysen, and also depot for the heavy motorised artillery belonging to the army HQ.
- Sarpsborgs festning - deactivated land fortress with two forts near Sarpsborg
- Oscarsborg festning - Coastal fortress near Dröbak in the inner part of Oslofjord.
- Rauöy coastal battery - A battery with 15 cm guns on the island of Rauöy, in the outer part of Oslofjord (there were more batteries on the western side of the fjord).

On the morning of the 9:th of April 1940 the following military units was situated in the area:

- II/A.R.1 in Fredrikstad (8x75mm field guns and 8x120mm howitzers. All horse drawn)
- 1. Div HQ in Fredrikstad
- 2. Div school (parts) in Fredrikstad (weak company)
- 1. Div school in Halden (company strength)
- Marine guard unit in Fredrikstad, guarding a destroyer under construction (platoon size).
- A guard platoon at Höytorps fort
- Two artillery school platoons at Höytorps fort
- A small guard detachment (26 men) at Sarpsborgs fortress

Norwegian installations and mobilization

At 04:00 the HQ of 1.Div in Fredrikstad got a message from Oslo that a mobilization order was in process and was to follow within a couple of hours (a lot of paper work to be done I guess). The commander of 1.Div, Gen. Erichsen, immediately began the process of a full mobilization, and when the order came and turned out to be a partial mobilization with the 11:th April as first day of mobilization, he decided that it was too late to change his previous order.


A.R.1, had their depots in Ski. Officers and some men turned up on 9th April and began organizing the stuff. During the day reports came, first of German landings at Moss, south of Ski, then of a German column moving north from Moss toward Ski. As no organized units was available to defend Ski, the depots was hastily evacuated over Glåma to the Askim area, with as much equipment as possible. Here the transport company (Bilkp.7) of the area was essential. They managed to mobilize and then help with the evacuation of depots already on the 9th. The only artillery saved was however two 75mm guns. The men and weapons saved from the depots was organized into the Askim detachment. It turned out that the German column wasn't heading for Ski, but passed by in great haste on their way to Oslo. The depots in Ski wasn't occupied until the 11:th April, and the Norwegians could continue to secure more equipment in small "raids" to the depots.


I.R.1 had their depots in Fredriksstad, Here mobilization began on the 9th. As the position was regarded as too exposed to German advances the depots and men were however evacuated to the area around Fossumströkets fortress (near Mysen). There the organization of I and II/I.R.1 as well as the local defence battalion of I.R.1 was finished by the 12:th of April and that day the organization of an improvised III/I.R.1 began.

Fossumströkets fortress:

Fossumströkets fortress had two rather strong forts, Höytorp and Trögstad, each with two 12 cm guns and two 7.5 cm guns in turrets, as well as eight old 8.4 cm guns in pits. In addition Höytorp fort had four 12 cm howitzers. The fortress was still on active status, but in latter years the main emphasis had turned from the fix installations, that was regarded as obsolete, to the organization of two modern motorized artillery battalions. One battalion of eight 12 cm howitzers and one battalion of twelve 10,5 cm guns. In addition there were small arms for about three battalions stored at the fortress. The result was a mess! The invasion caught the fortress in a process of shuffling around the ammunition in the fortress to make room for the new guns and their ammunition. The result was that only a few hundred shells could be found for the 12 cm turret guns and no ammunition whatsoever for the 12 cm motorized guns. Moreover only two of the twelve 10,5 cm guns could be used as they were the only ones with rubber for the tires (it is not entirely clear why the rest couldn't be used on a provisory basis, without the rubber). Apart from the general confusion there were also a shortage of trained personell, as many of the men in the organization lived in areas occupied or cut off by the Germans (a common problem for the Norwegians).

Sarpsborgs fortress:

Sarpsborgs fortress had two forts dominating the Glåma river around Sarpsborg, Greåker fort with two12 cm guns in turrets, west of the city, half way to Fredrikstad, and Ravnebergets battery with two 10.5 cm and four 7.5 cm guns, northeast of the city. The fortress had reserve status, which meant that no men, except for a small guard unit, were assigned to it in case of mobilization and that all material and installations was prepared for long time storage. A number of men gathered at Greåker fort, and together with the guard unit there were about 90 men defending the fort. They were unable to prepare the guns though, as they were partly dismantled and prepared with some thick grease, that they didn't manage to remove. They requested a weapon technician from Fossumströket but didn't get any.

Ravnebergets battery was guarded by ten men. Unlike in Greåker they were able to prepare the guns, but they didn't have the men to man them.

Norwegian movements before the 12th of April

Gen. Erichsen (the district commander) decided on the 9th to concentrate his forces around Mysen, protected from the Germans by the Glåma river line, and supported by the Fossumströket fortress. Next question was whether to defend the position or go north to unite with the 2.Div north of Oslo. The communication with HOK was broken, but finally they managed to get in contact with the over command by connecting through Sweden. Over the very noisy connection they got an order to defend their position.

The already mobilized II/A.R.1 was already on the 8th April ordered to take a dispersed formation, ready for march. On the 9th they were ordered to march to Mysen, using night marches, and to take cover during the days (to avoid air attacks). They arrived at Mysen on the 11th and were ordered to Askim, to support the Askim detachment (see above), defending the river crossings.

I and II/I.R.1 began their mobilization in Fredrikstad, but were ordered north to Mysen to finish their mobilization. When they arrived there I/I.R.1 were immediately ordered to march up to the Fetsund bridge over Glåma (north of lake Öyeren and east of Oslo), to protect the north flank. The battalion commander did however claim that the troops were too exhausted after mobilization and march to be able to do that, and the order was recalled. That was unfortunate as they would have arrived before the Germans took the bridge. Instead two weak patrols (10 men each) was sent to guard the two roads leading south from Fetsund (one on the east side of Öyeren and the other through the forests further east (through Aursmoen). Especially the eastern road was also extensively blocked with trees over the road.

German movements up to the 12th of April

When the first and second follow up waves had reached Oslo, in the morning of the 11:th of April, Falkenhorst felt secure enough in Oslo to begin offensive actions. Now the main fighting formations of the 163:rd and 196:th infantry divisions had arrived. The 181:st div should arrive within a couple of days.

In the original plans I.D.163 and I.D.196 should immediately press forward toward Bergen and Trondheim, while Östfold should be left isolated, for I.D.181 to take care of later. Stronger than expected resistance north of Oslo and high losses for I.D.163 and I.D.196 during the sea transport as well as reports of big Norwegian troop concentrations building up in the Askim-Mysen area southeast of Oslo did convince Falkenhorst that it was necessary to delay the northern thrust and eliminate the Norwegian troops in Östfold first. The task was given to I.D.169.

According to General Pellengahr, commander of I.D.196, he was at his first meeting with Falkenhorst in Oslo on the 10th April, given the order to break through toward Trondheim. At about two o'clock in the night toward the 11th General Engelbrecht of I.D.163 came to his quarter and said that due to the Norwegian mobilization (which they had hoped would never come) his orders were changed. His first objective would be to secure the area south east of Oslo (Östfold) to the Swedish border and prevent a linkup between the units mobilizing there (foremost I.R.1) and the units mobilizing northeast of Oslo. This "secondary" mission was not to his liking, and one might read between the lines that he suspected Engelbrecht to be behind this somehow.

Pellengahr estimated that one regiment would be sufficient for the task. I.R.345, which was hardest hit by losses during the transport from Germany, would stay in Oslo and regroup. I.R. 340 would go east through Lilleström, to isolate Östfold from north, while I.R.362, under Oberstleutnant Schaller, reinforced by I/A.R.233 and a platoon from bicycle squadron 233 got the task to attack the units of the 1st Norwegian Division mobilizing in Östfold and secure the area.

On the morning the 12:th of April three columns left Oslo. They will be called the north, middle and south column. 

North column (by foot and horse):
Commander: ?
1 battery/I/A.R.233.
1 platoon/bicycle squadron 233.

The north column marched east from Oslo and down on the west side of lake Öyeren and finally joined the middle column west of the Fossum bridge. The reason for this maneuver is not entirely clear to me. Either they expected some resistance in that area (totally clear of Norwegian troops) or they were aimed at another river crossing, north of the one the middle column approached. A river crossing they didn't find or didn't attempt for some reason.

Middle column (improvised motorization):
Commander: Major Wilck
reinforced company of I/I.R.324 under Haubtmann Arno Manthey. (Mot.streifabt./I/I.R.324 or Jagdkommando Manthey)

The middle column had the mission to cross river Glåma at Askim and destroy the troops mobilizing at Fossumströkets fortress. They moved south with the south column, and then turned east on the main road to Askim and Mysen, that crosses river Glåma on the Fossum bridge near Askim.

South column (improvised motorization):
Commander: Major Georg Maetschke
2 batteries from I/A.R.233.
1 platoon from bicycle squadron 233.

The south column followed the main road toward Fredrikstad, with the mission to clear the Fredrikstad-Sarpsborg-Halden area from Norwegian troops. Initially they marched south, but when General Pellengahr found that out, at noon, he ordered an improvised motorisation, using requisitioned Norwegian vehicles. 

On the 11th the brige at Fetsund was occupied by the Germans (on the 10th a motorized unit on a recon mission used the bridge, but no guards were left at the bridge.

Detachment Gutsche (improvised motorization):
Commander: captain Gutsche
1 platoon from kp.8/I.R.340
1 platoon from kp.11/I.R.340
1 platoon from kp.14/I.R.340 (37mm AT-gun)

On the 12th there were also a fourth column beginning to test the roads leading south, east of lake Öyeren. It was called detachment Gutsche from the commander, captain Gutsche. It was detached from IR340, which was assembled in the Lilleström area, east of Oslo. It was motorized and its mission was to link up with the columns advancing on Mysen.

The situation on the Norwegian side the 12:th of April

On the morning the 12 April the Norwegian troops were deployed as follows:

North front:

The important bridge over Glåma at Fetsund was taken undamaged by the Germans on the 11th after the Norwegian 2.Div, responsible for the defence of the area, had withdrawn to the north on the 10th without fight (more about that sometime in the future).

Two patrols (10 men each) was sent to the area on the 10th, to report any German moves. They were positioned at the two roads leading south, east of lake Öyeren

Company Orre (5 leaders, 60 men, 2 HMG, 3 LMG) at Trögstad church.

The roads leading south from Fetsund, east of lake Öyeren, was extensively blocked by trees. The one along the lake less than the others though.

West front:

The Askim detachment was an ad hoc unit consisting of the already organized artillery battalion II/A.R.1 and other personnel from A.R.1 hastily organized into infantry units. The detachment was divided into five bridge groups to cover the five bridges and dams crossing Glåma at the river bend south of lake Öyeren.

The bridge groups from north to south were:

Solbergfoss: 5 leaders, 73 men, 3 HMG
Langenes: 6 leaders, 65 men, 2 HMG
Fossum: 10 leaders, 120 men, 8 HMG
Kykkelsrud: 4 leaders, 40 men, 2 HMG
Vamma: 4 leaders, 40 men, 2 HMG

Reserve: a small improvised company
a half battery (2 guns) of 75mm guns.
II/A.R.1 (attached on 12th April):
Two batteries of 75mm guns and one battery of 120mm howitzers around Askim.

("leaders" are officers and NCOs, though Norway didn't use that distinction)

Situation map for the morning of the 12th of April

South front:

A local defence company in Fredrikstad was ordered to Mysen, and left Fredrikstad in the morning.
A naval guard detachment (about a platoon), guarding the destroyer being under construction at the ship yard, left the city in the evening.

Greåker fort west of Sarpsborg (just east of the bridge on the road to Fredrikstad) had 90 men with light weapons (none of the guns in the fort was available, as described above).


The two recently mobilized field battalions of I.R.1 (I and II/I.R.1) was assembled in the area Slitu-Jörntvedt-Ultveit (near Mysen) for rest and exercises.

The school battalion, built around the 1.Div school (the recruits undergoing their initial training), was positioned at Eidsberg and Rakkestadselva (a small river) south of the main position around Mysen, about half way to Sarpsborg.

An improvised third field battalion of I.R.1 (III/I.R.1) was organised in Slitu, around the school of 2.Div, that was in Fredrikstad on exercises when the invasion came.

A motorized half battery with two 75mm guns was positioned near Trögstad church, together with the supply train.

Fossumströkets fortress with Höytorp and Trögstad fort, had four 12 cm guns and two 7.5 cm guns in turrets, and two motorised 10.5 cm guns, ready to fire.

The battle begins

The middle column, with "Jagdkommando Manthey" in the lead, came to the Glåma bridge at Fossumströket shortly after noon on the 12th [2], or at about 07:00 [1]. Not expecting any serious resistance, the company drove toward the bridge, loaded on nine busses. Two busses in the front and nine following about 1km after.  When the first two busses, approaching the bridge on the road which goes beneath a steep cliff, had to stop for a roadblock on the western end of the bridge, the Norwegian machineguns open up fire from the other side of the river. It is an ideal ambush position and the German losses are heavy. According to their own records they had 12 dead, which would also typically mean between 30 and 40 wounded. 

Situation map for the morning of the 12th of April

As the rest of the German column advances on the bridge, and the Norwegian commander decides to blow up the bridge. The destruction of this bridge, as well as most other major bridges was planned already in peacetime, and explosives as well as necessary equipment was stored nearby. There are also three chambers for the explosives in the bridge. In spite of all the preparations the destruction is problematic though. First the electrical ignition fails. There is a good old fashioned tar fuse as backup though, and covered by all available machineguns the pioneer sergeant Sekkelsten runs out on the bridge and ignites it. The charges explodes, but the bridge just lifts a bit and then falls back to rest. What did happen? We will never know, but probably the reason was that after the destruction plans had been worked out, the surface of the bridge was improved with coating of reinforced concrete, without any modifications of the destruction plans.

Major Wilck investigated the situation, and described it as "A strong improved enemy position. A massive 100m long bridge over Glåma, slightly damaged. Strong current in the river. Steep cliffs down to the river. Very strong fortified position in the mountainside*. Enemy concealed in strong positions. Own artillery still unavailable". (the citation is my translation from a Norwegian translation [2])
*) An old fortification on the German side of the bridge.

Now the Germans occupied the heights on the western side of the river, and for the rest of the day there were a more or less continuous firefight with both machineguns and artillery participating on booth sides. Meanwhile the Mantheys force tried the flanks by making probing attacks on the railway bridge at Langenes, one kilometer to the north, and at the dam at Kykkelsrud, about two kilometers to the south. At booth sites the attacks were successfully repulsed, and the railway bridge were destroyed. Norwegian sources also mentions German attempts to cross the river over the ice and by boat, but the German sources I have seen cited does not mention any such moves [2]. As false reports on German advances were legio on the Norwegian side, I tend to believe that this is an example of that. There were no new attempts by the Germans to cross the river at Fossumströket during the day.

Wilck ordered the 7.cmp of II/IR362 forward, together with an anti tank platoon, and later some infantry guns and a MG-platoon. The regimental commander Oberstleutnant Schaller also arrived at the scene, and they decided to attack during the night, in the cover of darkness.

At midnight a white signal light blinded the Norwegians and, in the cover of darkness and fire from the German machineguns, parts of crossed the bridge and established a foothold on the eastern side. The Norwegians were surprised and was first not aware that the Germans crossed the bridge, but then an intensive firefight began, with Germans trying to expand their bridgehead, using hand grenades, while the Norwegian machine guns fired down at them more or less blindly, and German at- and infantry guns, as well as machine guns tried to take out the Norwegian machine guns.

After half an hour Major Wilck crossed the bridge. At about that time the Norwegian commander, Captain Solie, had gathered a small force and made a counter attack on the bridge. The German fire support on the other side of the river could not give effective support any more, as they didn't know where the German advanced elements were. Still the Norwegian attack was met with intensive fire.  Cpt. Solie was hit by several bullets and killed, and the attack bogged down.

Two hours after the initial crossing the rest of could cross the bridge.

Without any sizeable reserve, with the communications breaking down, and now with the commander killed, the defense began to crumble, and at about 05:30 (04:30 German time) Mantheys force crossed the bridge to continue the attack out of the bridge-head, held by 7.comp.

Situation map for the morning of the 13th of April

German machine gun in action in the advance on Askim

The next Norwegian defence line was at the western outskirts of the town Askim, where Group Gleditsch were deployed. Around 6 o'clock in the morning they opened fire against the Germans, advancing along the main road. The German advance is halted and they consolidate their position. Major Wilck establishes a command post east of the river, at the school building (skole) near Rom. Probing attacks by the Germans fails to break the Norwegian resistance, but a counterattack by the infantry company of Group Gleditsch toward Rom also fails. The Norwegians manages to localise the German command post and disrupts the Germans considerably by shelling it, as well as their assembly areas. Group Gleditsch, while strong in machine guns and artillery support, did however lack the infantry to protect the flanks of the wide battlefield, so when the Germans attacked at 12:00 on a wide front, it quickly became clear that a retreat was necessary. At 12:30 retreat was ordered. First the artillery had to withdraw and meanwhile the machine guns had to keep the Germans at distance, while they slowly outflanked the Norwegian positions. The result was that the artillery could retreat in good order, but the machine gun company had serious losses. At 15:30 Askim fell, and after that it was just independent HMG-teams on trucks, and artillery fire against the roads, that delayed the German advance. Late in the evening, at 22:00 the first Germans entered Mysen. 

In the meantime the Norwegian HQ had tried to build a defence line around Höytorp fort just east of Mysen. The commander Carl Erichsen was in however in doubt over the overall strategy. He saw three possibilities.

1) An attempt to break out to northeast, to link up with the Norwegian troops at Kongsvinger.
2) To defend a front anchored at the fortifications at Mysen and Trögstad.
3) To withdraw and form a defensive line at the lakes around Örje. Try to hold it a few days and then withdraw into Sweden, unless an Allied landing in the Halden area has given new opportunities.

At a staff meeting 19:00 Erichsen decides to go for alternative 3, a withdrawal to Örje. The alternative to move north is ruled out because he erroneously thinks that the Germans already controls all usable roads toward Kongsvinger. Alternative 2 (a defense around the forts) is ruled out because the front is considered too long for available troops. A reason might also be that one battalion has ignored or misunderstood the order to take one part of the line, and instead continued backward, leaving a big gap in the line. A general sense of defeatism may also be at hand. According to some reports the spirit among the troops were still good though, and the order the retreat came as a surprise.

The retreat over the single road between Mysen and Örje on the night between the 13th and 14th April quickly bogged down to a huge traffic jam. And in Örje, some unidentified troops began shooting at the column. The result was a demoralizing panic. In the evening it was decided that the whole force should be withdrawn into Sweden. Attempts had been made to get permission from the Swedish to just go through Sweden up to Kongsvinger, but this was turned down. In the end the troops were interned in Sweden for the rest of the war. In Sweden they formed the nucleus of the Norwegian brigade.

The Germans never pursued the retreating Norwegians beyond Mysen. On the 14th they began a careful attack on Höytorp fort.

The forts surrendered without any serious resistance, despite order to hold out as long as possible. Höytorp at 14:16 on the 14th April. Trögstad on the 15th, without any fight. Due to the course of events this had no serious impacts on the rest of the campaign though, even if the example of Hegra fort east of Trondheim shows what a determined defence of a fortified position could accomplish. 

1) Krigen i Norge 1940, Operationerna i Östfold
The official Norwegian history of the land operations.
2) Vi dro mot nord, Sven T Arneberg and Cristian Hosar
A Norwegian book using German sources to describe the war from German point of view.