Adelheid von Hessen (c1323-aft1371)

Adelaide of Hesse (1324–1371) was a daughter of Henry II, Landgrave of Hesse, and his wife Elisabeth of Thuringia. Adelaide was a member of the House of Hesse.

Unhappy marriage
On 29 September 1341, Adelaide married Casimir III the Great, King of Poland. This was Casimir's second marriage, after the death of his first wife, Aldona of Lithuania. Casimir had no male heir, though he had two daughters, Elizabeth and Kunigunde. On 29 September 1341, Adelaide was crowned in Poznań Cathedral. The marriage was very unhappy, Casimir started living separately from Adelaide soon after their marriage.

Annulment
Their loveless marriage lasted until 1356. Casimir separated from Adelaide and married his mistress Christina. Christina was the widow of Miklusz Rokiczani, a wealthy merchant. For bigamy and for his womanizing Casimir got into severe trouble with the clergy.

Casimir continued living with Christine despite complaints by Pope Innocent VI on behalf of Adelaide. The marriage lasted until 1363/1364 when Casimir again declared himself divorced. They had no children. The marriage to Adelaide was annulled in 1368. Then Casimir married his fourth wife Jadwiga (Hedwig) of Żagań. This marriage produced another three daughters.

With Adelaide still alive and Christine possibly surviving, the marriage to Jadwiga was also considered bigamous. The legitimacy of the three last daughters was disputed. Casimir managed to have two of his daughters, Anna and Kunigunde legitimatized by Pope Urban V on 5 December 1369. Jadwiga the younger was legitimatized by Pope Gregory XI on 11 October 1371.

Later life
After the annulment of her marriage, Adelaide went back home to Hesse. After her ex husband's death, she fought for her property rights. She spent the rest of her life in Hesse until her death in 1371, aged around forty-seven.