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In page Family of Vladimir the Great:

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Vladimir had several children whose maternity cannot be established with certainty. These include two sons, Stanislav of Smolensk and Sudislav of Pskov, the latter outliving all of his siblings. There is also one daughter, named Predslava, who was captured by Bolesław I in Kiev and taken with him to Poland as a concubine. Another daughter, Premyslava, is attested in numerous (though rather late) Hungarian sources as the wife of Duke Ladislaus, one of the early Arpadians.[citation needed]