Mieszko II Lambert
He was the son of the Lotharingian count palatine Ezzo (955–1034) and his wife Matilda (979–1025), a daughter of Emperor Otto II and his consort Theophanu. He was a member of the Ezzonian dynasty. Otto's elder brother Herman became Archbishop of Cologne in 1036; his sister Richeza married the Polish king Mieszko II Lambert in 1013.