Mas'ud ibn Abd Allah al-Bayzawi, known as Baba Rukn al-Din, a 14th-century Sufi mystic. According to the inscription at his tomb's entrance he died in 769/1367-68. His domed mausoleum in the Takht-e Foulad cemetery of Isfahan was commissioned by Shah Abbas and is registered Iranian national heritage. (Sources: WikiShia; Wikidata Q5950688.)