Overview
Mstivoj (925? - 995) was an Obodrite prince (princeps Winulorum) from 965 or 967 until his death. He inherited his position along with his brother Mstidrag from their father Nako in an unknown year.
Name
Mstiwoj is an old Slavic name popular among West Slavs and East Slavs, cognate with the Slavic word for vengeance (pol. mścić, cz. mstít, or ukr. mstiti) and "woj" or "wój" means "warrior". Thus the name has meaning "Avenger of warriors" or "Avenger warrior". Another forms of the name are: Mistivir, Mistiuis, Mistui, Mistuwoi, Mistiwoi, Mystiwoi, Mistivoj, Mstivoj and Polish Mściwój. The Christian name of Mstivoj was Billung - baptised after his probable godfather Hermann Billung.
Biography
In 983, the brothers were leaders of the great Slavic revolt, which German historiography labels the Slawenaufstand, which followed news of the Emperor Otto II's defeat at the Battle of Stilo. He raided far to the west and even destroyed the relatively new city of Hamburg that year. There are two accounts of his life and his reasons for abandoning Christianity.
According to Adam of Bremen:
A Slavic prince named Billung married the beautiful sister of Bishop Wago of Starigard and had with her a daughter Hodica and a son Mstislaw, whom he, taking advantage of his jealousy of the Saxons, goaded into hatred of Christianity and his mother until, having so offended his wife, he began to connive against Christianity and the bishops.
From Wikipedia (CC BY-SA 4.0).