Who married Bolesław I of Masovia?

Bolesław I of Masovia (Polish: Bolesław I Mazowiecki; 1208 – ca. 25 February 1248), was Polish prince member of the Polish House of Piast, Duke of Sandomierz (only a part) during 1229–1232, Duke of Dobrzyń during 1233-1247 and Duke over whole Masovia during 1247–1248.

He was the second son of Konrad I of Masovia and Agafia of Rus. He was probably named after his great-grandfather, Bolesław III Wrymouth. The death of his older brother Przemysł in 1228 left him as the eldest surviving child of his family.

Anastazja Aleksandrówna – córka księcia bełskiego Aleksandra Wsiewołodowicza. Pomiędzy rokiem 1245 a 1247 wyszła za mąż za księcia mazowieckiego Bolesława I, ich małżeństwo było bezdzietne. Po śmierci pierwszego męża w 1248 powtórnie zawarła małżeństwo z bojarem węgierskim Dymitrem, który identyfikowany jest z Dymitrem Abą.