Editing Casimir III the Great (section)

===Hedwig of Żagań===
In about 1365, Casimir married his fourth wife [[Hedwig of Sagan|Hedwig of Żagań]]. She was a daughter of [[Henry V of Iron]], Duke of [[Żagań]] and Anna of Mazovia. They had three children:
*[[Anna of Poland, Countess of Celje]] (1366 – 9 June 1422); married firstly [[William, Count of Celje|William of Celje]]; their only daughter was [[Anne of Cilli|Anne of Celje]], who married [[Jogaila|Jogaila of Lithuania]] when he was king of Poland (as Władysław II Jagiełło). Anna married secondly Ulrich, [[Duke of Teck]]; they had no children.
*Kunigunde of Poland (1367 – 1370)
*Jadwiga of Poland (1368 – ca. 1382)

As Adelheid was still alive (and possibly Christina as well), the marriage to Hedwig was also considered bigamous. Because of this, the legitimacy of his three young daughters was disputed.<ref>{{cite news|url=https://historia.org.pl/2017/11/19/nieszczesliwy-malzonek-kazimierz-wielki-bigamista-do-kwadratu/ |title=Nieszczęśliwy małżonek. Kazimierz Wielki – bigamista do kwadratu |access-date=28 March 2020}}</ref> Casimir managed to have Anna and Kunigunde legitimated by [[Pope Urban V]] on 5 December 1369. Jadwiga the younger was legitimated by [[Pope Gregory XI]] on 11 October 1371 (after Casimir's death).<ref>''Pope Gregory XI: the Failure of Tradition'' {{ISBN|978-0-819-15463-7}} p. 119</ref>