He was the brother and successor of
Vratislaus II (died 14 January 1092) as the third son of
Bretislaus I and
Judith of Schweinfurt. He did not succeed as
king, because his brother had only been elevated to the royal dignity for life by the
Emperor Henry IV without the establishment of a hereditary monarchy. Before he became duke of Bohemia, he had long ruled over southern parts of
Moravia, as junior sons typically did in this period of Bohemia, as duke of
Brno and
Znojmo from 1054. ==Marriage ==