During the period from 1400 to 1600 A.D., the Arabian Peninsula witnesses fragmented rule and struggle for control over the Holy Cities of Islam. Although Mecca and Medina are initially tied to Mamluk Cairo, Ottoman power is recognized in the early sixteenth century. Annual pilgrimage as well as east-west trade continue to be essential for the region. While local traditions of art and architecture remain strong, Cairo and Istanbul are also important sources of inspiration.