'Büffel' (i) was the German air operation to deliver reinforcements and supplies to the beleaguered units of Generalleutnant Eduard Dietl’s 3^rd Gebirgsdivision, involved in a growing land battle for the vital port of Narvik in northern Norway, by the aircraft of Generalleutnant Hans Geisler’s X Fliegerkorps (22 May/9 June 1940).

The operation was undertaken under the direct command of Generalfeldmarschall Hermann Göring’s Oberkommando der Luftwaffe within the context of the Norwegian campaign following the 'Weserübung' invasion of Norway

During this Norwegian campaign, Narvik and the area round it saw significant fighting, initially from 9 April between the German forces landed by the 10 destroyers of Kommodore Friedrich Bonte’s Gruppe I and the Norwegian forces of Generalmajor Carl Gustav Fleischer’s 6^th Division. This latter was better prepared for war than any other formation of the Norwegian army as it had been mobilised and kept on duty during the 'Talvisota' winter war in Finland. The Norwegians were subsequently reinforced by other Norwegian units to a strength of between 8,000 and 10,000 men, and by a swelling number of troops under British and French command to raise the eventual total to 24,500 men. Unlike those involved in the campaign in southern Norway, the Allied troops in Narvik would eventually outnumber the Norwegian troops.

At the outset Dietl was not well placed, for his 2,000 men were outnumbered. But after all 10 German destroyers had been sunk in the two naval battles of Narvik, about 2,600 German sailors joined in the land battle, and another 290 German specialist troops arrived after travelling via Sweden in the guise of health care workers. During the last three to four weeks the Germans were also reinforced by about 1,000 men air-dropped over Bjørnefjell as part of 'Büffel' (i), thus bringing the total number of Germans to around 5,000.

The outlook for the German force seesawed between good and bad several times. On occasions, the entire operation was controlled directly from the German high command in Berlin, where Adolf Hitler’s mood apparently changed constantly and the German leader several times considered ordering Dietl’s force to withdraw. Intelligence agents captured later in the war also stated that Dietl himself had been considering crossing the Swedish frontier with his troops to be interned, but it has been suggested that a German agent, Marina Lee, infiltrated the headquarters of Lieutenant General C. J. E. Auchinleck in Tromsø and obtained the British battle plan, and thereby settled Hitler’s and Dietl’s nerves.

The first phase of the German landing had the advantage of surprise, but as noted above the Norwegian troops in northern Norway had been mobilised for a three-month neutrality watch during the winter of 1939/40 and had therefore trained together. In the period 9/25 April the Norwegian forces suffered three catastrophes, however. First, the forces protecting Narvik were unable to resist the Germans largely as a result of the inaction of the local commanding officer, Oberst Konrad Sundlo (later a member of the fascist government of occupied Norway), who ordered his men not to challenge the invaders; second, around 200 soldiers from the Narvik garrison who had escaped capture and were blocking the railway to Sweden were taken by surprise while resting at Bjørnefjell, most of the men being captured; and third, the so-called 'Trønder Battalion' sent to hold Gratangsbotten was subjected to a surprise attack, suffering losses which ruined its morale and effectively knocked it out of the remainder of the campaign. Nevertheless, as a result of mounting Norwegian pressure and difficulties in keeping their forward units supplied, the Germans abandoned Gratangsbotn and withdrew from Lapphaugen and the Gratang valley, following the 'Battle of Gratangen'.

At the start of May, the Norwegians began an advance to the south in the direction of Narvik. Once it had become clear that the Allies would mount their main effort in Narvik during mid-May, the Norwegians then altered the axis of their advance toward Bjørnefjell.

The British arrived first in 'Rupert' (i) and established their headquarters in Harstad on 14 April. In the following days three British battalions were deployed mainly at Sjøvegan, Skånland (where a naval base was established) and at Bogen. Later they were deployed to the south of the Ofotfjord, at Ballangen and Håkvik. In May most British troops were withdrawn from the Narvik area and redeployed southward to Nordland, in order to delay the German advance there.

The initial British detachment was reinforced on 28 April by a French expeditionary force, under the command of Général de Brigade Marie Emile Antoine Béthouart. Three battalions of Alpine troops and two battalions of Lieutenant-colonel Magrin-Verneret’s 13eme Demi-Brigade de Légion Étrangère were deployed to both the north and the south of the Ofotfjord, but later the northern sector would be the main French area of operations. Four Polish battalions arrived on 9 May under French control, and were first deployed to the north of the Ofotfjord before being redeployed to the area to the south of the fjord. Early in June the Polish units were grouped into Général de Brigade Zygmunt Bohusz-Szyszko’s Polish 1ère 'Carpathian' Demi-Brigade des Chasseurs Alpins.

In addition to their other problems, the Allies had difficulty in deciding how best to retake Narvik and the strategically vital railway which allowed high-grade Swedish iron ore to be delivered to the ice-free port Narvik for shipment to Germany. There was no unified Allied command, and as a result co-operation between them was not always smooth. Even within the British forces, Major General P. J. Mackesy and Admiral the Lord Cork and Orrery, the army and navy commanders, had difficulty co-operating: Cork advocated a swift and direct attack from the sea while Mackesy advocated a cautious approach from both sides of the Ofotfjord. In the end Cork was given command of all the Allied forces.

In the second week of May, the Norwegian advances against the Germans to the east of Gratangseidet were the most significant movements on the Narvik front. In addition, on the Norwegians' right flank, French mountain troops advanced up the Laberg valley supported by a company of Norwegian ski troops. In the south the Allies did not have much success, and in the area to the north of the Ofotfjord they were stationary. The Norwegians continued their successful mountain campaign and in mid-May the Allies took the initiative and achieved significant successes.

Both Paris and London had been growing impatient with the slow Allied progress in the Narvik area, and the French commander, Béthouart, pressed for more decisive action. The cautious land approach was abandoned and an amphibious attack was launched at around 24.00 on 12 May. This attack was directed at Bjerkvik and preceded by a naval bombardment from British warships in the Herjangsfjord. Then the men of the French Foreign Legion were landed, together with five light tanks. The French took Bjerkvik and Elvegårdsmoen, and advanced north-eastward to the area from which the Germans were withdrawing and southward along the eastern side of the Herjangsfjord.

The plan also required Polish troops to make a land advance toward Bjerkvik on the western side of the fjord, but the terrain delayed the Poles, who did not arrive before the capture of Bjerkvik.

It had also been part of the plan for French and Norwegian troops to advance from the north in order to box the Germans in, but co-operation problems between the Norwegian and French commanders left a gap through which the Germans escaped. Despite this, the Allies had a clear path north of Narvik and planned to attack over the Rombaksfjord. Once again, though, the attack was stalled while the Allies waited for the full establishment of an air support capability at the airfield of Bardufoss.

At 23.40 on 28 May a naval bombardment began from the north. One Norwegian and two French battalions were to be transported across the Rombaksfjord and advance on Narvik from the north. In the south the Polish battalions were to advance toward Ankenes and the inner part of the Beisfjord. The maximum capacity of the landing barges was 290 men and the troops of the first wave could not be reinforced for 45 minutes. Even so, these first troops were able to get a foothold on Ornes by the time the rest of the French and the Norwegians were landed. The French moved westward toward Narvik and eastward along the railway. The Norwegians moved toward Taraldsvik mountain, circled round it and moved down toward the town.

The German commander had decided before 07.00 to evacuate Narvik, and the German troops thus retired along the Beisfjord. This was the first major Allied land victory of the war. It seemed now that it was only a matter of time before the Germans would have to surrender, for they were being compressed from the north by the Norwegians, from the west by the French, and from the south-west by the Poles. A German last stand at Bjørnefjell seemed probable, but events elsewhere in Europe now came to their rescue. The British government had already secretly decided on 24 May to evacuate the British forces in 'Alphabet' (i), and this fact became apparent in the following days. During the night of 24/25 May, Cork received orders to pull back, but under cover so the Germans would be prevented from interfering.

The Allied commanders agreed that an attack on Narvik would disguise the retreat and allow the destruction of Narvik’s harbour. The Norwegian government and commanders were first told of the Allied decision early in June, and this news was initially greeted with disbelief and then with bitterness. The Norwegians still hoped to defeat the Germans alone and, as late as 5 June, one of the two Norwegian brigades was ordered to attack.

The Norwegian government also explored the possibility of creating a neutral but free northern Norway. This plan proved fruitless, and on 7 June the king and government were evacuated to the UK. All of the Allied troops were evacuated from Narvik in 'Alphabet' (i) during the period 4/8 June 1940.