Cairo's political influence diminished significantly after the Ottomans supplanted Mamluk power over Egypt in 1517. Ruling from Constantinople, Sultan Selim I relegated Egypt to a province, with Cairo as its capital. For this reason, the history of Cairo during Ottoman times is often described as inconsequential, especially in comparison to other time periods. However, during the 16th and 17th centuries, Cairo remained an important economic and cultural centre. Although no longer on the spice route, the city facilitated the transportation of Yemeni coffee and Indian textiles, primarily to Anatolia, North Africa, and the Balkans. Cairene merchants were instrumental in bringing goods to the barren Hejaz, especially during the annual hajj to Mecca. It was during this same period that al-Azhar University reached the predominance among Islamic schools that it continues to hold today; pilgrims on their way to hajj often attested to the superiority of the institution, which had become associated with Egypt's body of Islamic scholars. By the 16th century, Cairo also had high-rise apartment buildings where the two lower floors were for commercial and storage purposes and the multiple stories above them were rented out to tenants.