In 1086, and after six years of marriage, Duchess Judith gave birth a son, the future Boles*aw III Wrymouth. This event changed Zbigniew's situation drastically. Now with a legitimate son and heir, both Zbigniew's and Mieszko's positions were threatened by Duke W*adys*aw I. In the case of Mieszko, he was forced to accept the situation due to the popularity of the latter among the nobility; however, in 1089 the Mieszko died under mysterious circumstances, probably by poisoning.
Zbigniew
Mieszko