Abu Ayyub al-Ansari, the companion and standard bearer of Muhammad, had died during the first Siege of Constantinople (674–678). As Mehmed II's army approached Constantinople, Mehmed's sheikh Akshamsaddin discovered the tomb of Abu Ayyub al-Ansari. After the conquest, Mehmed built Eyüp Sultan Mosque at the site to emphasize the importance of the conquest to the Islamic world and highlight his role as ghazi.