Religious elements in Iranian culture were also produced and sustained by non-specialist believers. Since even ‘orthodox’ Shia practices did not depend predominantly on a central institutional authority such as a papacy, localised authority and religious choice were important. Many religious traditions encourage the independent activity of believers, whether in the lives of individual ascetics or mystics (Hindu, Christian, Buddhist, Muslim) or by ‘lay’ provision of religious ritual, education and welfare (charity, pilgrimages, Methodist classes, Jewish Passover). Muslim traditions have their own historic features, notably a lack of sacraments like Christian baptism or communion in which priests act as irreplaceable intermediaries between God and the community of believers. Core religious duties such as prayer, fasting and pilgrimage are managed by Muslim believers themselves, and the authority of ‘ulama (important as it was and is) rested primarily on their role as interpreters and transmitters of texts, laws and traditions. In Shia communities there were a number of key arenas in which believers played direct roles in religious culture and practices. Although the establishment of Twelver Shiism as the dominant form of Islam in Iran during the sixteenth and seventeenth centuries was led by rulers and ‘ulama, it also involved the development of popular, community-based religious traditions. Intense attachment to the persons of the Twelve Imams (especially ‘Ali and Husein) was expressed in rituals of pilgrimage to shrines associated with them and their kin, and in commemoration of the martyrdom of Husein. Although encouraged by Shi’a ‘ulama, they were shaped by ordinary believers, drawing on localised mystical, ecstatic, customary or millenarian traditions.