Jihad

Arabic sources for the early conquests report agreements between conquerors and conquered, including the famous "Pact of 'Umar." The "people of the Book" (who were eventually considered to include Zoroastrians in addition to Jews and Christians) are granted protection of their persons and property and are allowed to practice their religion with certain constraints. They must pay jizya, which at first meant a collective tribute but which soon referred to a poll tax levied on individuals and households, derived from Koran 9:29 ("Fight those who believe not in God and the Last Day and [who] do not forbid what God and His Messenger have forbidden—such men as practice not the religion of truth, being of those who have been given the Book—until they pay the tribute [ jizya ] out of hand and have been humbled") (translated by Arberry, 1:207).

Here are the foundations of the dhimma, the "protection" of non-Muslims who live under the rule of Islam. People living under this protection could not be enslaved and were free to pursue whatever professions they liked. However, non-Muslims living outside the lands of Islam could be and often were captured and enslaved. Forced conversion was not allowed, following a clear Koranic principle (2:256) and in fact happened only in exceptional instances. Islamic jurists represented the world as divided between an Abode of Islam (Dar al-Islam) and an Abode of War (Dar al-Harb). Since the only legitimate sovereign is God and the only legitimate form of rule is Islam, the rulers of the Abode of War are mere tyrants, and the normal state of affairs between the two abodes is war. The Muslim state—in classical theory its leader, the imam—may conclude a truce with those rulers for a maximum of ten years but not a permanent peace. Some jurists added an intermediate Abode of Truce, but this did not alter the territorial character of the doctrine of jihad. This doctrine does not aim at the immediate conversion of populations or individuals but rather at the extension of God's rule over all the world, until "the religion is God's entirely" (Koran 8:39).