Sunni Islam was not a singular movement or the result of any one person's approach to religion, but rather a broad tradition stemming from diverse and organic developments in the early Muslim community.
One of Sunnism's crucial components is a perspective, evolved over the course of the 1st to the early 3rd Islamic centuries, which privileged the early Muslim community and its unity as a pious ideal. This perspective also solidified the primacy of the Prophet's Companions, especially Abu Bakr and Umar, and most importantly, emphasized adherence to the Prophet's custom, his Sunna, as the path to proper Islamic worship and legitimate Muslim identity.
Because Sunnism is a label for a set of beliefs and traditions within the broader tradition of Islam, there are no specific founders per se. There are, however, important individuals and crucial historical components of Sunnism that can be said to be foundational. The evolution of Sunnism was gradual; it was not a pre-formed ideology that issued abruptly. Like all sectarian delineations, it would also eventually contain its own subsets and divisions. The main centers of sectarian affiliation in the early period of Islam were, in fact, outside Arabia, in Syria and Iraq, where the first ruling dynasties, the Umayyads and Abbasids respectively, had their capital cities. Abbasid Caliphate (green) at its greatest extent, c. 850:Public DomainAs such, the continued administrative and cultural legacies of both Byzantium and Persia affected the development of theological and political perspectives in the early Muslim world.
The medieval Muslim community was never a monolithic or simple collective group, and the elaboration of the historical perspective described above was neither simple nor instantaneous. The term "Sunnism" itself reflects the later phrase "ahl al-Sunna" (the people of the custom of the Prophet) and is the result, rather than generator, of any particular theological or political view. Over the 1st and 2nd centuries of Islam, which correspond to the 7th and 8th centuries of the Common Era, several groups whose existence turned out to be short lived nevertheless influenced what would, by the 3rd century A.H./9th century C.E. come to be known as Sunnism. One of the most decisive aspects of which groups and individual ulama (scholars) would become central to articulating the historical vision of Sunnism was the patronage and support of the Abbasid regime (8th-13th centuries C.E.), ruling from Baghdad.
As noted, a hallmark of Sunni Islam, which in basic tenets (the "five pillars" of shahadah, prayer, fasting, almsgiving, and pilgrimage) is identical to any sect of Islam, is its vision of the primacy of the unity of the Muslim community (the umma) and its earliest leaders, notably the Prophet himself and his successors and Companions. Because this vision was necessarily constructed upon a framework of scholarship that revolved around hadith, scholars who specialized in hadith were crucial to the articulation of Sunnism. Early scholars, such as Ibn Sa‘d (d. 784) and Ibn Hanbal (d. 855), played a critical role in the pre-Sunni (or, as it has been called, proto-Sunni) elaboration of approaches to Islamic doctrine and practice. The consolidation of hadith literature is therefore another foundational aspect of Sunnism.
There is no centralized doctrinal council or concentrated spiritual authority for all of Islamic society. Processes that led up to the formalization of Islamic law, the shariah, were therefore multi-faceted. There are four schools of Sunni law that survived the vicissitudes of history and still exist today. (Though there are other Sunni schools of law, they are followed by very few people and are relatively unknown.) These four madhahib (schools of law) are named for four great teachers whose methodologies and approach to hadith and practice were most extensively expounded upon after their deaths by generations of students and scholars. All four of these agree about basic doctrine, but differ somewhat in terms of the execution of certain ritual aspects of Islam, and in their approaches to the interpretation of sources. They all consider one another, however, equally valid. The four remaining schools of Sunni law and their eponymous founders are:
The Hanafi School, named after Abu Hanifa (d. 767). He was born in Kufa (modern-day Iraq) around 702. Today, many Muslims of West and Central Asia, the Caucasus, the Balkans, Iraq, and Turkey are Hanafis.
The Maliki School, named after Malik ibn Anas (d. 796) Malik's ideas were deeply rooted in Medina, and they place an even greater emphasis on the practice of the Companions of Muhammad and their descendants. Many Muslims in Africa adhere to the Maliki school, with some significant exceptions, including Egypt.
The Shafi‘i School, named after Muhammad ibn Idris al-Shafi‘i (d. 820) who was a student of Malik's. He taught in Iraq and Egypt. Many Muslims all over the world, including Indonesia, Egypt, Malaysia, Singapore, Somalia, the Levant, India, Sri Lanka, and Yemen follow this school.
The Hanbali School, named after Ahmad bin Hanbal (d. 855), who was born in Baghdad. He was a student of al-Shafi‘i and was also an important figure in early Muslim theological disputes, which led to his persecution by the Abbasid caliph al-Ma'mun.