TDIH - January 26 This Day in (Medieval) History: January 26 661 – The Rashidun Caliphate came to an end with the assassination of the caliph Ali ibn Abi Talib, cousin and son-in-law of the Prophet Mohammad. 738 – Death of St. John of Dailam, Syrian monk. 945 – Constantine VII overthrew Byzantine co-emperors Stephen and Constantine. 946 – Death of Eadgyth (Edith of Wessex), wife of Otto I, King of the East Franks. 1186 – Death of Ismat ad-Din Khatun, wife of Saladin. 1390 – Death of Count Adolph IX of Holstein-Kiel. 1436 – Birth of Henry Beaufort, who later became the Duke of Somerset and a commander for the Lancastrian faction during the Wars of the Roses. 1500 – Vicente Yanez Pinzon landed in Brazil, the first European to do so.