world, a "Renaissance" whose physical artifacts survive. In many places a person or group would endow a waqf to maintain a lodge (known variously as a zawiya, khanqah, or tekke) to provide a gathering place for Sufi adepts, as well as lodging for itinerant seekers of knowledge. The same system of endowments could also pay for a complex of buildings, such as that surrounding the Süleymaniye Mosque in Istanbul, including a lodge for Sufi seekers, a hospice with kitchens where these seekers could serve the poor and/or complete a period of initiation, a library, and other structures. No important domain in the civilization of Islam remained unaffected by Sufism in this period. Modern era Opposition to Sufi teachers and orders from more literalist and legalist strains of Islam existed in various forms throughout Islamic history. It took on a particularly violent form in the 18th century with the emergence of the Wahhabi movement. Around the turn of the 20th century, Sufi rituals and doctrines also came under sustained criticism from modernist Islamic reformers, liberal nationalists, and, some decades later, socialist movements in the Muslim world. Sufi orders were accused of fostering popular superstitions, resisting modern intellectual attitudes, and standing in the way of progressive reforms. Ideological attacks on Sufism were reinforced by agrarian and educational reforms, as well as new forms of taxation, which were instituted by Westernizing national governments, undermining the economic foundations of Sufi orders. The extent to which Sufi orders declined in the first half of the 20th century varied from country to country, but by the middle of the century the very survival of the orders and traditional Sufi lifestyle appeared doubtful to many observers. However, defying these predictions, Sufism and Sufi orders have continued to play a major role in the Muslim world, also expanding into Muslim-minority countries. Its ability to articulate an inclusive Islamic identity with greater emphasis on personal and small-group piety has made Sufism especially well-suited for contexts characterized by religious pluralism and secularist perspectives. In the modern world, the classical interpretation of Sunni orthodoxy, which sees in Sufism an essential dimension of Islam alongside the disciplines of jurisprudence and theology, is represented by institutions such as Egypt's Al-Azhar University and Zaytuna College, with Al-Azhar's current Grand Imam Ahmed el-Tayeb recently defining "Sunni orthodoxy" as being a follower "of any of the four schools of [legal] thought (Hanafi, Shafi’i, Maliki or Hanbali)