The 'Battle of Hegra Fortress' was a German and Norwegian engagement in the Norwegian campaign within 'Weserübung' (15 April/5 May 1940).

In this engagement, a small force of Norwegian volunteers manning a fortified position resisted a numerically superior German force. After initial fighting around the Meråker railway line, the Norwegians pulled back into the Hegra fortress, in the Stjørdal municipality of Trøndelag county, and held off a number of German attacks before surrendering on 5 May as one of the last Norwegian units active in southern Norway.

The Norwegian defence was based on 250 volunteer soldiers and a single volunteer nurse. Most of the men were from the area of Hegra, Stjørdal snf Trondheim, but included three Swedes, and these were equipped with bolt-action Norwegian rifles as well as a number of Danish and US machine guns. The fortress had artillery in the form of four comparatively modern 105-mm (4.13-in) and two 75-mm (2.95-in) guns, as well as four older Krupp 84-mm (3.31-in) field guns. The artillery had a maximum range of between 6,560 and 9,840 yards (6000 and 9000 m). Many of these men had been mobilised into the Norwegian 3^rd Artillery Regiment at Øyanmoen camp at Værnes air base, and were transferred to Hegra to continue the Norwegian mobilisation after the Germans had reached the camp. Hegra fortress had been intended only as a temporary refuge for the artillery regiment, but became the centre of the volunteers' war in 1940.

The German attackers were initially mountain troops of the 138^th Gebirgsjägerregiment, which was part of Generalmajor Eduard Dietl’s 3^rd Gebirgsdivision, which landed at Trondheim on 9 April. Later, between 20 and 27 April, the Germans replaced the 138^th Gebirgsjägerregiment with units of Generalleutnant Kurt Woytasch’s 181^st Division, and the mountain infantry regiment was were sent to the north to try to reinforce its sister units on the Narvik front. By the end of the battle the German forces employed against Hegra fortress comprised largely one infantry battalion at Hegra and one one company of Gebirgsjäger in the nearby village of Sona. Additional units were deployed in the village of Elvran and in the Selbu region.

The fort at Ingstadkleiva, which had been built early in the 20^th century and since been mothballed. and which later become known as the Hegra fortress, was not intended by either of the sides at a battlefield, and only became import when a Norwegian artillery officer, Major Hans Reidar Holtermann, began to organise troops to resist the German invasion forces advancing from Trondheim. Holtermann first travelled to the camp at Værnes to mobilise his 3^rd Artillery Regiment during the afternoon of 9 April, but the Germans arrived at Stjørdal station on the following day, and by 10.30 were approaching the camp. As his regiment was not yet ready for combat, Holtermann decided to move to what was at that point known as Ingstadkleiva fort for the completion of the regiment’s mobilisation. Thus, at 15.00 on 10 April, most of the personnel and equipment under Holtermann’s command arrived at the small mountain fortification of Ingstadkleiva fort. At this point, Holtermann was ordered to proceed with the mobilisation and otherwise do what he himself thought best. Holtermann thus began to gather and equip a force of local volunteers. After arriving at the fort, Holtermann first took occupied the buildings outside the mountain fortifications, not intending to defend the facility but only to employ it as a temporary base.

By 10 April, Holtermann already had 50 volunteers under his command and a steady stream of mostly local men continued to reach the fort. On 11 April, men of Holtermann’s unit returned to Værnes to remove more of the matériel and provisions still in storage there. As a result of the poor German security at the camp, the Norwegians were able to carry out their mission undetected, and the reclaimed supplies were taken in part to the fortress and in part to a number of nearby farms. When a force of 250 soldiers had been assembled, Holtermann had to turn away further volunteers as he could neither arm nor equip any more men. From 12 April the Norwegians worked to reactivate the fortress’s artillery, which was found to have plentiful ammunition, but no fire-control system or even the maps which would have made indirect fire possible. The proper artillery maps for the the fortress were in store at Trondheim and had thus fallen into the hands of the Germans on 9 April: these maps were used by the Germans during the siege to deploy artillery in places that the fortress’s artillery could not hit. The same day troops of Holtermann’s unit were positioned around Hegra railway station and Mælen bridge, and the Germans made their first attempt to secure the fortress’s surrender: a German major approached the fortress together in company with two Norwegian officers who had surrendered on this same day, but despite the best efforts of both the German officer and the two surrendered Norwegians, Holtermann refused to capitulate.

On the following day, Holtermann established contact with Generalmajor Jacon Ager Laurantzon’s 5^th Division for the last time during the Norwegian campaign, and in this telephone conversation was ordered to act as he saw best and, if possible, to hinder the Germans in their effort to gain control of the Meråkerbanen railway line to Sweden. In response to this instruction, 20 soldiers were sent to the village of Flornes to set up field fortifications and block the road and railway to Meråker.

On 14 April, the Norwegian troops stationed in Hegra village started to receive reports that a train loaded with German soldiers had left Hell railway station and was on its way to Hegra. Not long after this, a train approached Hegra station and ignored signals to stop, and in response to what the Norwegians interpreted as a German troop train trying to force its way through, the soldiers guarding the station opened fire on the approaching train, which was in fact carrying Finnish refugees home after the end of the 'Talvisota' winter war. The fire killed one Norwegian man and wounded two Finnish women. Later in the afternoon of the same day, the garrison’s sole female member joined when nurse Anne Margrethe Bang arrived from from Trondheim together with a consignment of medical supplies. The daughter of a doctor and trained in first aid, Bang stayed in the fortress for the duration of the siege, helping two military doctors care for the sick and wounded.

The first shots were fired by the fortress’s defenders on 14 April, when heavy machine gun fire damaged a German aeroplane and drove it away. More equipment and ammunition from Værnes reached the fortress on the same day.

At 05.30 on 15 April, the Germans had artillery support as they attacked the Norwegian positions at Hegra railway station, the Hegra road bridge and the Mælen bridge. Caught partially off guard, the Norwegian force at the Hegra road bridge and the railway station made a fighting retreat to the fortress in a period of some two to three hours. Early in the fighting, the Norwegians had demolished the Hegra road bridge, forcing the German infantry to cross the precarious ice of the frozen Stjørdal river under fire. At the Mælen bridge, the Norwegian defenders withdrew to the south. Four Norwegians were killed in and around Hegra, while another was killed at the Mælen bridge. Eight Norwegians were taken prisoner during this initial German attack.

As the German attack developed, the artillery of the Hegra fortress opened up to support the Norwegian troops under attack in the valley below, and later covered their retreat. The Norwegian artillery fire was directed at German artillery positions, machine gun nests and truck convoys pushing to the east in the direction of the Swedish border. The operator at Hegra telegraph station acted as an observer for the artillery at the fortress, which destroyed three pieces of German artillery and inflicted casualties on the attacking force.

As the Norwegian infantry pulled out of Hegra and moved along the road toward the fortress, the Germans pursued them until they reached an array of field fortifications blocking the road. Here the Norwegians held their ground and killed several of the attacking force’s men, including the attacking platoon’s leader, Oberleutnant Hans-Joachim Herrmann. After the end of this skirmish, as they went through the area to seize German arms and equipment, the Norwegians found a wounded German soldier, whom they brought on a ski sled to the fortress for medical care.

At the end of the first day of serious fighting, the Germans pushed on along the Meråkerbanen railway and broke through the blocking position at Flornes. The troops holding Flornes withdrew first to Meråker, then farther to the north to join other Norwegian forces. As night fell, German troops had occupied the areas around the villages of Hegra, Avelsgaard, Flornes, Ingstad and Sona. During the day, German warplanes had repeatedly flown over the Hegra fortress, from which the Norwegians had responded with small-arms and machine guns, damaging one machine, which crashed while attempting an emergency landing at Værnes.

The day after the German capture of the area surrounding the fortress, German warplanes again made repeated attacks with bombs and machine gun fire. German infantry probed the approaches to the fortifications but were driven off by artillery and heavy machine gun fire. In response, a German mountain howitzer brought up to Avelsgaard bombarded the fortress, destroying most of the houses outside the walls. One Norwegian soldier killed by a shell hitting the fortress’s parapet was the last Norwegian fatality of the battle.

On 17 April, the day began at 07.00 with a German bombardment from the air and by the howitzer position at Avelsgaard. At 09.00, a large force of German infantry attacked from the north-east, supported by machine gun positions situated a mere 150 m (160 yd) to the north of the fortress. The attack was halted only after it had reached the barbed wire entanglements directly in front of the Norwegian trenches. At this point, the attacking force was subjected to heavy fire at close range from artillery, machine guns and small arms, and thrown back. German bombers continued to hit the fortress throughout the day, knocking out both the telephone line and the electricity supply, neither of which was restored during the siege, so from this time onward all light inside the Norwegian tunnels and halls was provided by candles and kerosene lamps.

The day after their first unsuccessful attack, the German forces made another attempt at storming the mountain fortress. In preparation, the fortifications were subjected to heavy machine gun and mortar fire during the early daylight hours. A battalion of infantry was moved toward the fortress, but was hit by a blizzard while marching through no man’s land: the attacking units lost their bearing in the storm and fire fights erupted between groups of Germans mistaking each other for Norwegian patrols. The German attack therefore failed even before it could reach the Norwegian positions. Bombers and heavy-calibre artillery maintained a steady fire on the fortress throughout the day.

During the evening of 18 April, two Norwegian doctors, Sigurd Aarrestad and Peter Berdal, approached the German commander of the Hegra-Son area and asked for permission to pass through the German lines to evacuate wounded soldiers from the fortress. During the previous days' fighting many German wounded had been brought to Hegra village and the doctors therefore feared that there had probably been many casualties on the Norwegian side. The requested permission was granted, and the shelling of Hegra fortress was temporarily suspended while local volunteers made their way up to the fortress, pulling ski sleds for the wounded. While Aarrestad led the expedition, Berdal was held hostage by the Germans to ensure that the Norwegians returned from the fortress. When Aarrestad returned from the fortress a few hours later, he brought along nine wounded Norwegian soldiers and the wounded German. As part of the agreement, the Norwegian wounded did not become prisoners of war.

From around 25 April, the Germans abandoned their attempts to take the Hegra fortress by storm. The pressing need to remove the Norwegian force ended in large part after the important town of Steinkjer had fallen to the Germans on 21 April and the Allied advance from the north had been checked. The southern arm of the Allied counterattack had never swung to the north from Åndalsnes and had instead been directed to the Gudbrandsdal in order to support the Norwegian forces fighting there. As the immediate crisis for the German forces in Trondheim had now passed, they preferred to push to the south in order to link with forces advancing from Oslo. The German focus was therefore switched to the air and artillery bombardment of the Hegra fortress in an effort to pummel it into submission.

The ground fighting now took the form duels between the fortress’s guns and German field artillery, and skirmishes between German and Norwegian ski units undertaking reconnaissance patrols and delivering supplies of food, ammunition and fuel. Several Norwegian soldiers in these patrol actions. To counter German artillery sited in the blind zone of the fortress’s guns, the Norwegians positioned their two 84-mm (3.31-in) guns to cover areas the fixed guns could not reach. During the siege, the Norwegian guns targeted machine gun nests, artillery positions, command posts and ammunition depots in the surrounding area. On 23 April, one of the 75-mm (2.95-in) fixed guns was knocked out, one of the fortress’s command towers was destroyed and the water line was broken. The second 75-mm (2.95-in) gun was destroyed on 24 April. The fortress was under constant artillery fire and held out chiefly in order to be in a position to support the Allied offensive that was expected from the north.

On 25 April, the Germans employed a new weapon against the fortress when a seaplane dropped a 1800-kg (3,969-lb) bomb, destroying the houses outside the walls: the resulting fragments landed as far away as Hegra village several kilometres distant. From 29 April, the German artillery bombardment steadily increased in strength, with German guns reinforced by captured Norwegian 120-mm (4.72-in) howitzers from the arsenal in Trondheim, and on the following day one of the fortress’s three 105-mm (4.13-in) guns was knocked out. During the siege, more than 2,300 shells struck the fortress.

One of the ways in which Holtermann wished to provide direct support the main Norwegian war effort was the bombardment of the Værnes air base, the northernmost airfield in German hands and as such vital for the support of German forces in the area to the north of Trondheim. This was especially true for the Narvik front, which could not be reached by aircraft flying from bases farther to the south than Værnes. Recognising this fact, the Germans had used some 2,000 Norwegian collaborationists to expand expand and improve the base’s runways. Bombarding Værnes would have disrupted this work and at the same time impaired the bombing raids being flown against Norwegian forces fighting farther to the north. As Værnes is 7.1 miles (11.5 km) from Hegra and the fortress’s guns had a maximum range of only about 5.6 miles (9 km), this was impossible. For accurate firing, the effective range was a mere 4.3 miles (6.9 km). Efforts were made at the fortress to increase the guns' maximum maximum range by increasing their greatest elevation angle from 19° to 26°: this was attempted by the removal of part of the guns' shields and part of their mountings, but these failed as no welding equipment could be acquired to carry out the modifications. Even though no modifications could be carried out, one of the 105-mm (4.13-in) guns at Hegra opened fire in the direction of Værnes on 22 April, but with the gun firing at maximum elevation its shells still fell hundreds of metres short of their intended target.

The earliest attempt by the Hegra garrison to attack the airfield at Værnes had taken place on 14 April, when a Norwegian dog sled patrol spotted considerable German air activity at the base. Plans were made to manhandle one of the fortress’s 84-mm (4.31-in) guns to the nearby Blankhammeren hill, and from there bombard German targets, including the airfield, that were out of range from the fortress itself. The plan could not be implemented, however, before the German attack of 15 April brought large German infantry forces into the area and rendered the scheme impossible.

During the siege, the struggle of the Hegra fortress captured the attention of international media, and resulted in articles such as those in the The Daily Telegraph on 22 April and 2 May, and that in The Manchester Guardian on 16 April. The fortress was also mentioned in articles in Time magazine on 6 and 13 May.

News arrived by radio on 2 May of the Allied retreat from the Åndalsnes area, that the Germans had seized control of the Dovre line between Dombås and Støren, and that the Norwegian 4^th Brigade had surrendered in western Norway. This came on top of increasing supply problems, for the bread supply had run out on 30 April. On the next day, 3 May, the garrison started to destroy its artillery ammunition in preparation for surrender. The three Swedish volunteers who had endured the siege with the Norwegians were released from their duties and guided across the mountains to the Swedish border by a ski patrol. During the day, a radio message from Oberst Ole Berg Getz, the Norwegian commander in the Trøndelag area, was broadcast. Getz had surrendered his forces in Nord-Trøndelag and advised all Norwegian forces in Trøndelag to lay down their arms as the situation had become hopeless after the British retreat from the southern parts of Norway. The decision to surrender Trøndelag had been influenced by the radio broadcast of Neville Chamberlain, the British prime minister, announcing the end of the Allied campaign in southern Norway. On 4 May, destruction of radios, machine guns, rifles, carbines and other small arms was initiated and ski patrols were sent to carry out important documents. By 13.50 on this day, confirmation of Getz’s capitulation was received and the destruction of the fortress’s artillery began.

Early on 5 May, the Norwegian situation was such that there was very little food and water for only a few days, all other Norwegian and Allied forces in southern Norway had been withdrawn or had surrendered, and Hegra fortress was the last remaining pocket of resistance to the south of Nordland. At 05.00, Holtermann assembled his men in the tunnels and informed them of his decision to surrender the fortress. In a short speech, he thanked them for their efforts and then led them in singing the Norwegian national anthem. At 05.25 a white flag was raised over the fortress, and at 06.30 a force of 60 German soldiers and three officers arrived to accept the garrison’s surrender. Later in the day, 190 men and one woman marched out of the fortress and into captivity. At the time of the surrender, the Hegra fortress’s garrison comprised 14 officers, one technical officer, seven sergeants, one officer cadet, six corporals, 161 privates and nurse Bang.

After their surrender, the Norwegians were marched down to the Hegra railway station, from which they were transported by train. In Trondheim, the officers and Bang were taken off the train and interned at Trondheim cathedral school, while the NCOs and soldiers continued their journey to Lundamo in the Gauldalen valley. At Lundamo, the prisoners were interned in a barn for the night. On 6 May, the prisoners from Hegra were force-marched some 31 miles (50 km) to Berkåk, where a prisoner-of-war camp was established. At Berkåk, the prisoners were set at work at building an improvised road from the Orkla river near Berkåk across the woods to Brattset. This road was intended to help the German logistic system, which had been severely dislocated by the numerous bridges that had been blown by the Norwegian army during the preceding month. In part as a result of the poor physical condition of the prisoners after the harsh siege they had just experienced, the road was never completed despite threats of punishment made by the German camp commandant. At the end of May the German high command in Berlin announced that Adolf Hitler had personally ordered the release of Norwegian prisoners in recognition of the defence they had put up under exceptionally difficult conditions. The release of the prisoners from Hegra took place in stages, and by the middle of June the last had been let go.

Six Norwegian soldiers had been killed in action and another 14 had been wounded during the battle. All the Norwegian fatalities occurred during the first two days of the fighting. In the first years after the end of the war, Norwegian estimates of the number of German casualties were exaggerated: some suggested as many as 1,100 dead or wounded, but later research led to a substantially lower number of about 150 to 200 dead or wounded.