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. The Obotrites invaded Saxony and sacked the Cocarescemians' settlement, killing the men of arms-bearing age and carrying off the women and children into slavery. According to Widukind of Corvey, in the aftermath of Lechfeld, Otto pressed hard into Slav territory, where Wichmann and Egbert had sought refuge. Otto razed the Slav population centres and soon had encircled them; he offered to spare his enemies if they would surrender. 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 t