'Cäsar' (i) was a German spoiling attack in the aftermath of the only partially successful 'Doppelkopf' in the Baltic states to disrupt that part of the Soviet 'Bagration' strategic operation intended to divide Generaloberst Georg-Hans Reinhardt’s Heeresgruppe 'Mitte' and Generalfeldmarschall Ferdinand Schörner’s Heeresgruppe 'Nord' (essentially General Carl Hilpert’s 16th Army and General Ehrenfried-Oskar Boege’s 18th Army) with the ultimate objective of striking toward Siauliai (16/21 September 1944).
The operation was based on General Dietrich von Saucken’s reorganised XXXIX Panzerkorps, General Erhard Raus’s 3rd Panzerarmee having been placed under the temporary control of Heeresgruppe 'Nord', and started on 16 September in response to the Soviet 'Riga Offensive Operation' by General Hovhannes Kh. Bagramyan’s 1st Baltic Front, General Andrei I. Eremenko’s 2nd Baltic Front and General Ivan I. Maslennikov’s 3rd Baltic Front. By 21 September, however, the German undertaking had ground to a halt in the face of intense Soviet resistance after having penetrated only a few miles, and the German forces then went onto the defensive.
The Soviet forces attacked once again on 5 October in the 'Memel Offensive Operation', and five days later reached the Baltic Sea and finally isolated Heeresgruppe 'Nord' in what eventually became the Kurland pocket, though General Hans Gollnick’s XXVIII Corps was isolated from the remainder of 3rd Panzerarmee in a separate beach-head just to the south at Memel.