The battle, fought in Muhu, Estonia, resulted in the crusaders storming and capturing a fortress held by the Oeselians.

[1] In January 1227, when the sea had frozen hard, a large Crusader army was gathered after the call of the Papal legate William of Modena.

According to the Chronicle of Livonia, 20,000 troops had set out for Muhu from the estuary of Pärnu River and moved along the ice.

The besiegers threw rocks into the stronghold with bricoles, built a turret, and undermined the wall.

On the sixth day the Livonian army managed to break into the stronghold, where a ferocious slaughter took place.