The Battle on the Raxa river (German: Schlacht an der Raxa) was fought on 16 October 955 over control of the Billung march (in present-day Mecklenburg-Vorpommern, northeast Germany) between the forces of Otto I of Germany allied with the Rani tribe on one side, and the Obotrite federation under Nako and his brother Stoigniew (Stoinef, Stoinneg, Stoinegin, Ztoignav) with their allied and tributary Slav neighbours on the other.

While King Otto was distracted by his campaigns against the Magyars, his vassals Wichmann the Younger and his brother Egbert the One-Eyed instigated a Slav revolt in the Billung March.

A Slav embassy came to an assembly Otto held in Saxony and offered to pay annual tribute in return for being allowed self-government; "otherwise," they said, they would "fight for their liberty.

[1] According to Widukind of Corvey, who gave the only surviving detailed record of the battle, Otto I's campaign came to a halt at the bank of the Raxa river, where the Obotrites and their allies, led by Stoigniew (Stoinef), had taken a defensive position on the opposite embankment.

Otto's margrave Gero, together with the allied tribe of the Ruani – most probably the earliest mention of the Rani[8] – secretly moved to a distinct part of the river to build three bridges, while a feint assault by the remaining forces distracted Stoigniew's army.