sentences:  After the death of Lothair in 1137, Lothair's son-in-law Henry the Proud and Margrave Albert the Bear fought over the Duchy of Saxony.Pribislav took advantage of the struggle to rebel against the authority of the Holy Roman Empire by destroying the new castle of Segeberg and invading Holstein in Summer 1138.Saxons from Holstein and Stormarn under the command of Henry of Badewide led a massive counterattack the following winter.