The Ottoman Empire was an Islamic polity that originated in early-fourteenth-century Anatolia. Islam had been established in Anatolia before the emergence of the empire, but between the fourteenth and sixteenth centuries the religion spread with Ottoman conquest to the Balkan Peninsula and central Hungary. This does not mean that the population was uniformly Muslim. In many parts of the Ottoman Empire, most notably in the Balkan Peninsula, Christians formed a majority of the population, and even in areas where Muslims formed a majority there was usually also a minority of non-Muslim inhabitants. Unlike some of the rulers of western Europe, the Ottoman sultans never attempted to impose religious uniformity. Islam was, however, the dominant religion, and the political structure of the empire reflected this fact. The dynasty itself was Muslim and, before the reforms of the nineteenth century, with rare exceptions, non-Muslims could not hold regular political office or military command.

Christians and Jews were able to participate in the maintenance of the empire by serving as tax farmers or contractors supplying, for example, cloth for Janissary uniforms or materials to the naval arsenals, but they could not serve as viziers, provincial governors, or army commanders. In the fourteenth and fifteenth centuries a few Christian fief holders in the Balkans retained their positions in the years immediately after the Ottoman conquest but, as their descendants converted to Islam, this phenomenon disappeared within a generation. In the Balkans, too, some Christian groups served as military auxiliaries into the sixteenth century. More important in the dayto-day lives of the sultan's subjects, the system of law courts also reflected the dominant position of Islam. The Christian and Jewish communities maintained their own courts for regulating intracommunal affairs, but only the network of Muslim courts covered the entire empire, and only Muslim courts were open to all the sultan's subjects, irrespective of religion. Any cases involving Muslims or a Muslim and a non-Muslim had to be heard in the Muslim court and, in principle, a non-Muslim could not testify against a Muslim. The exclusion, therefore, of non-Muslims from political office and the supremacy of Islamic law guaranteed the hegemonic position of Islam within the Ottoman Empire. At the same time, the imposition of jizya, a poll tax on adult non-Muslim males, and the occasional short-lived imposition of dress restrictions on non-Muslims, symbolized the inferior position of Christians and Jews.

FORMS OF ISLAM
By the time of the emergence of the Ottoman Empire in the fourteenth century, Islam was fully formed as a system of belief with its associated intellectual, legal, and cultural attributes. The central concept of the religion was "knowledge," or ˓ilm, meaning specifically the knowledge of God through revelation. God had revealed himself to mankind through the missions of the prophets, among whom Abraham (Ibrahim), the monotheistic founder of the Ka˓ba at Mecca, Moses (Musa), and Jesus (˓Isa) held especially revered positions. The recognition of Abraham, Moses, and Jesus as prophets before the final revelation of Islam justified the tolerated but subordinate positions of Jews and Christians within the Ottoman Empire and other Islamic polities. God's final and most perfect revelation was through the prophet Muhammad, "the Seal of the Prophets." The primary text of revelation is the Koran. This is regarded by Muslims as the literal word of God transmitted to mankind through the medium of the Prophet. The record of the sayings and actions—the hadith—of the Prophet, as an exemplar to mankind, form the second text of the revelation. It is through the Koran and hadith, therefore, that man can know God and, in principle, these form the foundation of knowledge, or ˓ilm.

A seeker after knowledge had first to study Arabic, the language of revelation and the language of science, which acquired a role in the Ottoman Empire and in the Islamic world as the universal language of religion, somewhat similar to the role of Latin in western Christendom. The study of the sacred texts and the sciences in general also required a grounding in logic and rhetoric. With these tools at his disposal, a scholar could embark on any of the specialized branches of ˓ilm, which developed as discrete, though interrelated genres: the interpretation of the Koran (tafsir), the study of hadith, theology (kalam), dogma ( ˓aqa˒id) or law (fiqh). These were the sciences through which one acquired a knowledge of God, and which therefore formed the central curriculum of Ottoman and other Islamic colleges. Subsidiary sciences—for example, the life of the Prophet (sira), history (ta˒rikh), the vitae of saints or scholars by generation (tabaqat) —served to strengthen sectarian or dynastic identity, and all came to form genres of Ottoman literature. Of the sciences, it was the study of law (fiqh) that enjoyed the greatest prestige and made the greatest impact on communal and individual lives. It represented not exactly God's commands to mankind, as these are ultimately unknowable, but the best that humankind can achieve in its efforts to discover God's law.

It regulated not only secular affairs, notably in the sphere of family law, but also rituals such as ablution, prayer, fasting, and forbidden foods. The basics of the law, popularized as the "five pillars of Islam"—the profession of faith, prayer five times daily, charity, fasting during Ramadan, and the pilgrimage to Mecca—are something that every Muslim must know. In many respects, therefore, it was the adoption of Islamic law—the shar˓ or shari˓a —that gave Ottoman, and other Islamic societies, their distinctive form.

A person who had studied ˓ilm was an ˓alim ('one who knows [God]') and enjoyed great prestige. The plural of ˓alim is ˓ulama, and the ulema came to form a respected class within all Muslim societies, often, as in the Ottoman Empire, wielding political as well as legal and spiritual power.
˓Ilm was not, however, the only route to knowing God. Already in the early centuries of Islam some claimed to know God through direct revelation, a condition exemplified by the saying of al-Sarraj (d. 988): "There is no ˓ilm that is known and nothing that is understood except what exists in the Book of God, or is transmitted from the Messenger of God, or in what is revealed in the hearts of saints." In order to distinguish the knowledge of God acquired by direct revelation "in the hearts of saints," its adepts, the Sufis, referred to it not as ˓alm, but as ˓urf or ma˒rifa, both words having the sense of "knowledge." This doctrine had revolutionary potential, since a person claiming knowledge via direct divine inspiration could claim to be above the divine law as professed by the ulema. Indeed some Sufis, notably al-Hallaj (d. 909), who reputedly suffered death for declaring "I am God," did emerge, in the Ottoman Empire and elsewhere, as opponents of the religious and political order. What is more remarkable, however, is how tasawwuf, the faith of the Sufis—radically different from the religion of the ulema—came to form a branch of orthodox Islam.

In principle, ˓ilm and ˓urf are antagonistic in their fundamental beliefs. In orthodox belief, God created the world ex nihilo; he revealed himself through his prophets; the world will end with the Resurrection and the Judgment, where individuals will be judged and assigned in eternity to Heaven or Hell. In Sufi belief, all creation was originally one with God. God created mankind and the universe because "He was a hidden treasure and wished that He should be known." Since this separation from the Creator, all Creation has yearned to return to its Maker. The Sufi therefore yearns to be reunited with God, as the lover yearns for union with the beloved. In orthodox Islam, knowledge of God comes through written revelation whose interpretation is the preserve of the ulema. In Sufi belief, knowledge of God is acquired through direct experience, or "taste" of God.
There has at all times been antagonism between some of the orthodox ulema and the Sufis. For example, in the Ottoman Empire of the mid-sixteenth century, the jurist Ibrahim of Aleppo (d. 1549) and the Ottoman chief mufti, Çivizade Mehmed (d. 1542), adopted anti-Sufi positions, while the Sufis for their part conducted a literary polemic against these orthodox opponents. The poet Khayali (d. 1556/57) compared the orthodox ulema who could not recognize that God was in the world around them to "fish who are in the sea, but do not know what the sea is." Nonetheless, opponents of the Sufis remained a minority and tasawwuf in practice became an important strand of mainstream Islam in the Ottoman Empire.

Tasawwuf grew in importance through doctrinal development. In the developed Sufi theory of knowledge, the first rule that a Sufi must follow is obedience to the shari˓a. This precept brought tasawwuf within the bounds of orthodoxy. Second, the spiritual goal of most Sufis was not to declare "I am God," but to seek "annihilation of the self in God": the Sufi's soul became like "a drop of wine in the ocean of God's love." In other words, tasawwuf became quietist rather than activist. At the same time, tasawwuf became institutionalized. Different orders of Sufis formed around the memories of Sufi saints, and these organizations acquired properties and endowments, to preserve which they had to remain acceptable to orthodox Islamic regimes. Finally, the favorable opinions of al-Ghazali (d. 1111), perhaps the most influential Islamic thinker, made tasawwuf acceptable to most orthodox opinion. Some orders, it is true, remained unacceptable. In the Ottoman Empire, an offshoot of the Bayrami order of Sufis, which formed after 1450, adopted the activist belief that God is manifest in the human form, thus putting men—or at least their members—above the dictates of the shari˓a. These Sufis constituted an underground and ineffective, though persecuted, opposition to orthodox Islam and the Ottoman sultanate.