Kievan Rus%27:

Kievan Rus' also played an important genealogical role in European politics. Yaroslav the Wise, whose stepmother belonged to the Macedonian dynasty, the greatest one to rule Byzantium, married the only legitimate daughter of the king who Christianized Sweden. His daughters became queens of Hungary, France and Norway, his sons married the daughters of a Polish king and a Byzantine emperor (not to mention a niece of the Pope), while his granddaughters were a German Empress and (according to one theory) the queen of Scotland. A grandson married the only daughter of the last Anglo-Saxon king of England. Thus the Rurikids were a well-connected royal family of the time.

Please answer a question about this article. If the question is unanswerable, say "unanswerable". Who did Yaroslav's sons marry?
daughters of a Polish king and a Byzantine emperor