Al-Mahdi built himself a new, fortified palace city on the Mediterranean shore, al-Mahdiyya, removed from the Sunni stronghold of Kairouan. The Fatimids construct the Great Mosque of Mahdia in Tunisia. The Fatimids found a new capital city. A new capital city, al-Mahdia, named after al-Mahdi, is founded on the Tunisian coast due to its military and economic significance.