Stephen was born in
Landshut, the son of
Henry XIII, Duke of Bavaria and
Elizabeth of Hungary. His maternal grandparents were
Béla IV of Hungary and
Maria Laskarina. His mother introduced the name Stephen onto the
Wittelsbach dynasty with her youngest son. She was a sister of
Stephen V of Hungary, and may have named her son after him. To reduce the influence of the Wittelsbach,
Pope Nicholas IV refused his spiritual career in
Salzburg and Stephen became a co-regnant of his brothers. During the absence of Otto III in Hungary 1305-1308, Stephen was the only governing duke of Lower Bavaria. Stephen was an enemy of the
Habsburgs and died in 1310 during a war against
Frederick I of Austria. ==Marriage and children==