William IV of Forcalquier
William IV, Count of Forcalquier (1130-1208) was the son of Bertrand II Count of Forcalquier and Josserande de la Flotte. William, married Adelaide de Beziers, daughter of Adelaide de Beziers and Raimond Trencavel of Beziers Viscount of Beziers, of Agde, of Albi, of Carcassonne, and of Razès. He had a daughter Garsenda who married Rainou of Sabran, Lord of Caylar and Ansouis. His daughter Garsenda predeceased him so his grand daughter of the same name inherited his county at the age of 13. He signed the Treaty of Aix with Alfonso II who was in line to become Count of Provence betrothing her to Alfonso in marriage.
- Stuart, Roderick W. (2002). Royalty for Commoners, The Complete Known Lineage of John of Gaunt, Son of Edward III, King of England, and Queen Philippa (Fourth ed.). Baltimore: Genealogical Publishing Company.