The mosque of al-Azhar was built in the first years of the new Fatimid capital and completed in 972, and teaching began there within a few years. The irony of its later career is that the Fatimids were Ismaili Shia and founded it to propagate their own doctrine through trained missionaries. When Saladin ended Fatimid rule in 1171 that teaching was suppressed, and the institution was rebuilt over the following centuries as a centre of Sunni learning, eventually of all four Sunni schools of law, each with its own teaching circle and endowments.
Instruction was organised for most of its history around scholars rather than a syllabus. A student attached himself to a shaykh, worked through a text with him, and received a licence to transmit that text in turn. Residential lodgings were arranged by region of origin, which drew students from West Africa, the Nile valley, the Levant, Anatolia, the Indian Ocean and beyond, and made graduates a network as much as a class.
The modern institution is a state one. A law of 1961 added faculties of medicine, engineering and commerce, brought appointments under government control and made the Shaykh of al-Azhar an office of the state as well as of the scholars. Its Islamic Research Academy issues opinions that carry weight far outside Egypt, and its position on questions from bank interest to organ donation is reported worldwide. Al-Azhar's authority is real, contested and inseparable from the government that appoints its head, and any account of Sunni Islam today has to reckon with all three of those facts at once.