It is difficult to estimate how many ʿAlids there were by the late fifth/eleventh century. Al-Ṭabarī reports that al-Ma'mūn had the ʿAbbāsids counted in 200/815–6 and that this count yielded 33,000 men and women. If we assume that there were as many ʿAlids around that time, there must have been thousands more some 200 years later. This is a vast number of people, some of whom significantly shaped the history of Islam. Yet whether or not they became well known as rebels or rulers or eponymous founders of Islamic sects or were recorded in the history books, the ʿAlids were able to carry out a variety of roles in Muslim societies that few others were able to fill: as living links to the Prophet, as negotiators on behalf of a town or a people, as intermediaries between humans and the Divine.

From our current perspective, most significant was perhaps the ʿAlids' ability to bridge differences between Sunnis and Shiʿites. As the examples in this book have shown, not only were there Sunni and Shiʿite members of the Prophet's family, the ʿAlids were also able to move between the different communities, studying with eminent Sunni and Shiʿite scholars and inter-marrying with prominent Sunni and Shiʿite families. Throughout the centuries, ʿAlid shrines were visited and received patronage from Muslims of all denominations. A similar role transcending and bridging community divisions was in later centuries played by also Sufi shaykhs, who quite explicitly called themselves ‘the true ahl al-bayt’.