One concept related to jihad involved the Arabic phrases Dar al-Islam ("realm of Islam") and Dar al-Harb ("realm of war"). In the period of Islamic empire (even as late as the Ottoman Empire, ca. A.D. 1300-1918), the "realm of Islam" was the area under Islamic rule or influence. The word islam, translated literally, means "submission" (i.e., submission to the will of Allah). Thus, those living within the "realm of Islam" were considered (in theory at least) at peace with and among themselves because they were in submission to Allah's will.
The Dar al-Harb ("realm of war") took in all areas outside the "realm of Islam." These areas were the realm of war for two main reasons. First, since peoples living in the realm of war were not in submission to Allah's will, they were warring among themselves. Second, all Muslims ("those who submit" to Allah's will) were obligated to extend the realm of Islam to all areas of the known world. They could obtain this goal either by proselytizing or, if needed, by physically warring against the inhabitants of the realm of war. Islamic scholars (and lay Muslims) have interpreted the means of extending the realm of Islam in different ways throughout Islamic history-some in militant terms and others in more peaceful terms. Apart from this ambiguity of interpretation, one thing was definite: if the realm of Islam was attacked from outside, all Muslims had the duty to defend it against the realm of war. 5
