Hacı Alâeddin was an architect from Konya. He is known to have been the chief architect of the Eski Camii at Edirne with the assistance of the builder Ömer bin Ibrahim. Their contribution is acknowledged on the inscription plaque (kitabe) above the western portal of the mosque.Source
Ayverdi, Ekrem Hakki. Osmanlı Mi'mârîsinde Çelebi ve II. Sultan Murad devri, 806-855 (1403-1451): II. Istanbul: Baha Matbaasi, 1972.