Mosques were primarily an urban phenomenon, and in most of the thousands of small villages there were no mosques. Since that time their role has continued to expand, so that in 1987 mosques played important political and social roles as well as religious ones. Another religious institution of major significance was a special building known as a hoseiniyeh. Hoseiniyehs existed in urban areas and traditionally served as sites for recitals commemorating the martyrdom of Husayn, especially during the month of Moharram. In the 1970s, some hoseiniyehs, such as the Hoseiniyeh Irshad in Tehran, became politicized as prominent clerical and lay preachers used the symbol of the deaths as martyrs of Husayn and the other Imams as thinly veiled criticism of Mohammad Reza Shah's regime, thus helping to lay the groundwork for the Revolution in 1979.
Institutions providing religious education include madrasehs and maktabs.
Madrasehs, or seminaries, historically have been important for advanced training in Shia theology and jurisprudence. Madrasehs are generally associated with noted Shia scholars who have attained the rank of ayatollah. There are also some older madrasehs, established initially through endowments, at which several scholars may teach. Students, known as talabehs, live on the grounds of the madrasehs and are provided stipends for the duration of their studies, usually a minimum of seven years, during which they prepare for the examinations that qualify a seminary student to be a low-level preacher, or mullah. Maktabs, primary schools run by the clergy, were the only educational institutions prior to the end of the nineteenth century when the first secular schools were established.