Officially known as the Sultan Ahmed Mosque, the Blue Mosque was completed in 1616 on the ground of the former Byzantine imperial palace, across from the Hagia Sophia. Its nickname came from its use of handmade İznik style ceramic tiles for the interior. It is built around a main dome, eight secondary domes and a cascade of smaller domes. Designed by Sedefkâr Mehmed Ağa, it incorporates Byzantine Christian elements of nearby Hagia Sophia with traditional Islamic style.