A leading Kalenderî sheikh of the Abdalân-ı Rûm, active from the end of Bayezid I's reign through Mehmed I and Murad II (late 14th-early 15th c.). Also called 'Sultan Varlığı' and 'Şücâüddin Baba', he is greatly revered today among Alevi-Bektaşi communities. His tomb stands in Arslanbeyli (Aslanbey) village, 6 km from Seyitgazi, which bore his name until 1968; the octagonal domed tomb was built in 921 (1515) by Kasım Bey. (Sources: TDV İslâm Ansiklopedisi; Eskişehir Provincial Directorate of Culture & Tourism.)