Constance of Sicily
Constance of Sicily (1324–1355) was a daughter of King Peter II and Elisabeth of Carinthia. Unmarried, she was an abbess at Messina and educated her brothers Louis and Frederick. After her mother died in 1352, Constance took over the regency for King Louis.
She ruled a kingdom torn by baronial feuds and the Black Death. Louis died of the plague in October 1355, and Constance followed him days later; their sister Euphemia then became regent for Frederick.