Isabella of Lusignan her half-brother King Henry III in 1254. After thirteen years of marriage Geoffery died. Isabella herself died on 14 January 1300 having most likely outlived all of her children. She had several grandchildren. Isabella also outlived all of her siblings (full and half). Isabella of Lusignan Isabella of Lusignan (c.1224 – 14 January 1300) was a daughter of Hugh X of Lusignan and his wife Isabella of Angoulême, Dowager Queen of England. Isabella was half-sister to King Henry III of England. She was Dame de Beauvoir-sur Mer et de Mercillac. Isabella's year of birth is unknown. She is mentioned in
Edward III of England France to perform the homage. The young Edward was accompanied by his mother Isabella, who was the sister of King Charles, and was meant to negotiate a peace treaty with the French. While in France, Isabella conspired with the exiled Roger Mortimer to have Edward deposed. To build up diplomatic and military support for the venture, Isabella had her son engaged to the twelve-year-old Philippa of Hainault. An invasion of England was launched and Edward II's forces deserted him completely. Isabella and Mortimer summoned a parliament, the king was forced to relinquish the throne to his son, who was proclaimed