Frederick the Simple
Frederick III , called the Simple, was King of Sicily from 1355 to 1377. He was the second son of Peter II of Sicily and Elisabeth of Carinthia. He succeeded his brother Louis. The documents of his era call him the infante Frederick, ruler of the kingdom of Sicily, without any regnal number.
Frederick III was born in Catania, and succeeded to his brother Louis in 1355 under the regency of his sister, Euphemia of Sicily. In his youth the reign was under the control of powerful Sicialian barons, in particular of Artale I Alagona. The beginning of Frederick IIIs reign was also plagued by intermittent wars with the Kingdom of Naples and also by the Black Death, to which his elder brother and predecessor had succumbed. OnDecember 1369 Frederick ordered all Jews to wear a badge indicating their heritage. The badge consisted of a piece of red material, not smaller than the largest royal seal men were required to wear it under the chin, and women on the chest. In 1372 he was able to come to peace terms with Naples and Pope Gregory XI, obtaining the title of tributary King of Trinacria.
Source: Wikipedia