'Donner' was the German withdrawal of Generaloberst Carl Hilpert’s 16^th Army and General Ehrenfried-Oskar Boege’s 18^th Army of Generaloberst Ferdinand Schörner’s Heeresgruppe 'Nord' to the 'Salaspils-Stellung' defence line between Salaspils and Balkas to protect Riga against the advance of General Andrei I. Eremenko’s 2^nd Baltic Front and General Ivan I. Maslennikov’s 3^rd Baltic Front (5/10 October 1944).

Like Generaloberst Johannes Friessner, his predecessor as commander of Heeresgruppe 'Nord', Schörner believed that the the evacuation of German forces from Estonia was a matter of the gravest urgency, despite Adolf Hitler’s adamant stance that this would not be allowed, and secretly prepared a ring of field defences in the area of the 16^th Army through which the 18^th Army could retire. Greater urgency was added to the local commander’s fears by the armistice between the USSR and Finland, which was signed on 19 September and, as far as Heeresgruppe 'Nord' was concerned, had the decidedly unpleasant side effect of providing the Soviet navy with access to the naval bases and waters of Finland’s south coast, and thereby reopening the central Baltic to Soviet warships. This raised the spectre of the German land positions in the Baltic states being outflanked from the sea, and in an effort to check, if not remove, the threat Hitler ordered the deployment of a single division on the islands covering the mouth of the Gulf of Riga.