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 their liberty." Reuter argues that this is indicative of a change in German governing practice: a change from overlordship, which the Slavs were willing to accept, to lordship, which the Slavs protested.