Editing Shiʿa (section)

==Buyid Period==
The [http://www.iranicaonline.org/articles/buyids Buyids] (945–1055) accorded the Shiʿa the most favorable conditions for elaboration and standardization of their tenets. In this period compilation of the major collections of Shiʿa [[hadith]] and formulation of Shiʿa law took place. This elaboration began with Muhammad ibn Yaʿqub al-Kulayni (d. 490), author of the monumental Usul al-kafī (the sufficient fundamentals), who was followed by such figures as Ibn Babuyah, also called Shaykh al-Saduq (d. 991), Shaykh al-Mufid (d. 1022), and Shaykh al-Taʿifah, or Muhammad ibn al-Hasan al-Ṭusi (d. 1067), by whom the principal doctrinal works of Shiʿi theology and religious sciences were finally established. This was also the period of other renowned Shiʿi scholars, such as al-Sharif al-Razi (d. 1015)—who compiled the sermons and sayings of ʿAli—and his brother, Murtaza ʿAlam al-Huda (d. 1044).

These intellectual activities continued after the fall of the Buyids through such Shiʿi scholars as Fazl al-Tabarsi (d. 1153), known for his monumental Quranic commentary; Razi al-Din ʿAli ibn al-Ta’us (d. 1266), theologian and gnostic; Nasir al-Din al-Ṭusi (d. 1273); ʿAllamah Ḥilli (d. 1326); and Haydar al-Amuli (d. after 1385), who established a new system of rational theology.

It was also in the Buyid period that two popular Shiʿi commemorations were instituted in Baghdad: [[Ashura]], marking the martyrdom of Imam Hussain on the tenth of the month [[Muharram]], which was observed with great religious fervor and zeal; and the Festival of Ghadir, commemorating the Prophet's nomination of ʿAli as his successor at Ghadir al-Khumm. It was also during this period that public mourning ceremonies for Hussain were initiated, shrines were built for the Imams, and the custom of pilgrimage to these shrines was more popularly established.

By the end of the Buyid era Shiism's basic beliefs had been completely formulated, leaving to the future only elaborations, interpretations, rationalizations, and certain adaptations and additions. Among the scholars who have enriched Shiʿi literature over the past eight hundred years—especially in philosophy, theology, and law during the Mongol, Ṣafavid, and Qajar periods—were such great figures of the Ṣafavid period as Mir Damad (d. 1631) and Mulla Sadra (d. 1640), masters of metaphysics with whom Islamic philosophy reached a new peak; Baha’ al-Din al-ʿAmili, theologian and mathematician; and the two Majlisis, the second, Muhammad Baqir, being the author of the largest compendium of the Shiʿi sciences, the Bihar al-anwar (Oceans of Light).

Although Ithna ʿAshari Shiism attained its final position under the Buyids who ruled over Baghdad and Iran, the Ismaʿiliyah and the Zaydiyah also consolidated their doctrinal positions at roughly the same time. The Ismaʿilis controlled Egypt, southern Syria, much of North Africa, and the Hejaz, and the Zaydis established their rule in northern Iran and Yemen. This political supremacy provided the Ismaʿiliyah and the Zaydiyah with opportunities to elaborate and standardize their doctrinal positions. By the end of the tenth century, all three branches of Shiism were thus firmly enough established to withstand the vicissitudes of history and the stresses of the sectarian role into which they were pushed by the Sunni majority.