How did the Abbasids support the holy cities of Mecca and Medina?

The Abbasid caliphate supported the holy cities of Mecca and Medina through a policy of strict religious observance and significant financial patronage. To demonstrate their commitment to these spiritual centers, the Abbasids devoted large sums of money to the maintenance and embellishment of the cities.1

Key contributions included:

• Pilgrim Caravans: The Abbasids organized and sent an annual pilgrim caravan from Iraq to the holy cities, facilitating the Hajj for many believers.1
• Public Works: The caliphs and their families invested in infrastructure to support the growing population and pilgrims. Notably, Zubaydah, the wife of Caliph Hārūn al-Rashīd, is credited with ordering the construction of the qanāt, a sophisticated tunneled conduit system designed to provide a reliable water supply to Mecca.1

These efforts were part of the Abbasids' broader strategy to bolster their legitimacy as leaders of the Muslim community, despite ongoing political challenges from various Alid pretenders who contested their right to the caliphate.1