Another forms of the name are: Mistivir, Mistiuis, Mistui, Mistuwoi, Mistiwoi, Mystiwoi, Mistivoj, Mstivoj and Polish Mściwój.
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.
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.
Then Dietrich of Haldensleben proclaimed that "the high-born niece of a great prince may not be given to a dog," whereupon Mstivoj, recruiting the Liutizi to aid him, devastated Nordalbingia with fire and sword.
Mstivoj's daughter Tove married in the spring of 962 Knut Danaást, the eldest son of Gorm the Old of Denmark.