The annual pilgrimage-hajj-to Mecca has existed since the rise of Islam. It is to be undertaken on specific days during the lunar "month of the hajj" and is one of the five "pillars" of Islam (along with bearing witness, prayer, alms-giving, and fasting). Mecca, however, is in a sovereign state (Saudi Arabia), and Muslims live around the world. Thus the politics of pilgrimage. As Bianchi shows, these are no minor matter. The annual number of pilgrims has increased some 20-fold over the past 50 years, reaching almost two million. To regulate these numbers, Saudi Arabia and other Muslim states have arrived at annual per-country pilgrim quotas, and international politics swirl around various other issues raised by the hajj. So too domestic politics, as illustrated by Bianchi's separate studies of the administration of the hajj in Indonesia, Malaysia, Nigeria, Pakistan, and Turkey. The ebb and flow of pilgrims in past decades (as well as data on country of origin, age, sex, and political affiliation) are presented in some 40 pages of appendixes. Guests of God, the fruit of a personal pilgrimage in 1989 (do not miss the pages recounting that) and more than a decade of research throughout the Muslim world, is a beautifully wrought study that tells much about the hajj and more.