'Ratweek' (i) was a British bombing offensive by Air Vice Marshal W. Elliot’s Balkan Air Force, undertaken in conjunction with Yugoslav partisan harassment operations against the German forces of Generaloberst Alexander Löhr’s Heeresgruppe 'E', and designed to hinder the latter’s evacuation of Greece to join with the main forces of Generalfeldmarschall Maximilian Reichsfreiherr von Weichs’s Heeresgruppe 'F' in Yugoslavia (1/7 September 1944).

The withdrawal of Löhr’s army group 1 was necessitated by the development of the Soviet autumn offensive of 1944 into the Balkans, followed by the defections of Romania and Bulgaria from the Axis cause. In the autumn there was thus a great chance that Löhr’s 345,000 German soldiers, sailors and airmen would be cut off in the southern Balkans.

Heeresgruppe 'E' was formed on 23 August 1944, and one day later was ordered to fall back into southern Yugoslavia along the line from Scutari to the Iron Gate pass via Skopje. However, by this time the Bulgarian 5^th Army, now fighting alongside the Soviets, had captured Nis behind the left flank of the proposed line for Heeresgruppe 'E', and Löhr was forced to adopt a line farther to the north, then establishing his headquarters at Sarajevo by 15 November.

In the course of this retreat the Greek guerrilla forces had harried the 315,000 retreating Germans (some 30,000 men having been left to their fate as garrisons of the Greek islands), and this effort was greatly supplemented by the activities of 'Ratweek' (i) which, however, failed to slow the German retreat sufficiently for Marshal Sovetskogo Soyuza Fyedor I. Tolbukhin’s 3^rd Ukrainian Front to cut the Germans' line of retreat by an advance farther west. As it was the Soviets with Yugoslav support captured Belgrade on 20 October, vindicating Löhr’s choice of a more westerly line of retreat through Skopje, Mitrovica, Novi Pazar and Visegrad rather than the more obvious line from Skopje to Nis, Kraljevo and Belgrade.