Wer heiratete Kasimir I. (Kujawien)?

Kasimir von Kujawien (polnisch Kazimierz I Kujawski; * ca. 1211; † 14. Dezember 1267) war als Kasimir I. ab 1233 Herzog von Kujawien, 1247–1261 Herzog von Sieradz und 1247–1267 Herzog von Łęczyca. Er war der Begründer der kujawischen Linie der Piasten.

Constance of Wrocław (Polish: Konstancja wrocławska) (c.1221–27 – 21 or 23 February 1257) was a princess of Silesia and the duchess of Kuyavia. She was a member of the Polish House of Piast and mother of Leszek the Black and Ziemomysł of Kuyavia.

Euphrosyne of Opole (Polish: Eufrozyna opolska) (1228/30 – 4 November 1292) was a Polish duchess and regent.

She was a daughter of duke Casimir I of Opole and his wife Viola, Duchess of Opole, and a member of the House of Piast. She was Duchess of Kuyavia from her first marriage to Casimir I of Kuyavia, and Duchess of Pomerania from her second marriage to Mestwin II, Duke of Pomerania. She acted as regent of the Duchy of Kuyavia during the minority of her son Władysław I the Elbow-high in 1267-1275.