http://en.wikipedia.org/wiki/Bonne_of_BohemiaJutta(Bonne) was originally betrothed to Casimir III of Poland, however this arrangement was broken and Casimir married Aldona of Lithuania instead. After Aldona's death, Casimir was betrothed to Jutta's elder sister Margaret, however this betrothal was also broken and Casimir remarried to Adelaide of Hesse.
What if this marriage pushed through?
Bonne of Bohemia had many sons would she provide Casimir male heirs like what she did with Jean II of Valois in OTL if she married Casimir III instead?