When Muhammad died, in 632, Islam could boast only semi-stable control over part of the Arabian peninsula. The prophet's territorial gains had been mainly pagan losses. Further expansion required conquest of Christian lands—a task that would prove all too easy, thanks to years of imperial and doctrinal wars.

To Islam's west lay Egypt and the rest of Christian North Africa. Once consolidated under the Roman Empire, by the sixth century the territory was divided between Latin-speaking Berbers in the west and Greek-speaking Byzantines in the east, with a few Baal-worshipers in the south.

Africa's theological divisions ran even deeper. Byzantines upheld the two-faceted definition of Christ's nature affirmed by the Council of Chalcedon in 451, but Egypt's Monophysite ("one nature") Christians, along with churches in Armenia and Syria, vehemently rejected it. African Christianity was also plagued by controversies among catholics, Donatists (who insisted that all other Christians were apostate), Nestorians (who disagreed with both Monophysite and Chalcedonian Christology), and radical desert ascetics.

To Islam's near north and east sprawled the massive, though fading, Persian Sassanid Empire. The Zoroastrian Persians had persecuted Christians severely in the fourth century, judging the new friends of Persia's old enemy, Rome, to be a threat. After a toleration edict in 409, though, the Persians opted to control the church rather than destroy it.

By meddling in ecclesiastical governance, Persia had sent the local church into serious decline by the turn of the seventh century. Conflict between Nestorians, the majority Christian group, and their sworn enemies, Monophysites, hastened the slide.

To the northwest lay the shrinking Byzantine Empire, the remains of Roman glory. By Muhammad's time, battles with Persia had forced the Byzantines to withdraw from provinces such as Egypt and Syria and protect their capital, Constantinople. The Egyptians and Syrians were glad to see them go, taking their high taxes and persecution of "heretical" churches with them.

Hail to the new chiefs

With the Middle East in such disarray, Muhammad's successors were able to make rapid gains. The Muslims proved to be both fearsome warriors and shrewd politicians, sometimes killing or uprooting their enemies, sometimes grinding them down with economic and religious oppression.

The first Islamic caliph (deputy), Abu Bakr, was murdered before he could make much of a military impact beyond central Arabia, but his successor, Umar, routed a Byzantine army in Syria and hounded the last Persian shah to his death. Damascus, Jerusalem, and the Persian capital, Ctesiphon, fell like dominoes.

Umar solidified control of the Arabian peninsula and assumed at least nominal authority over Persia's far-flung properties. He also built the first mosque in Jerusalem. But his stunning success created challenges.

Christians significantly outnumbered Muslims in most of Islam's new territories. In addition, Christians had diplomatic and medical expertise that Muslims lacked. Killing all of the Christians made no political sense, and in any case, the Qur'an advocates better treatment for "Peoples of the Book." Umar's solution, as described in his famous pact (see page 16), established Christians and Jews as dhimmi, or protected persons.

On the surface, the terms seem quite fair, especially for the seventh century. In exchange for paying extra taxes, dhimmi qualified for nearly all rights and protections under Islamic law. More importantly, unlike pagan Arabs, Christians and Jews were not forced to convert to Islam.

Christians thought they were getting a good deal. High taxes were nothing new, and Muslim authorities took no sides in the bitter doctrinal wars that divided the Christians. The Nestorian patriarch wrote to a fellow cleric, "They have not attacked the Christian religion, but rather they have commended our faith, honored our priests … and conferred benefits on churches and monasteries."

Stealth oppression

Unfortunately, seventh-century Christians failed to see the deeper threat of Umar's bargain. Modern apologists for Islamic tolerance generally make the same mistake. Protected status really meant second- or third-class status, with strictures guaranteed to erode all religions but Islam.

Granted, both Eastern (Byzantine) and Western (Roman) Christian powers put a high priority on enforcing what they deemed to be true religion, and neither was above using physical or civil coercion to achieve this aim—in the seventh century or for centuries afterward.

Indeed, Muslims apparently adapted parts of their policy on other religions from existing Christian codes. It is less often reported that Muslims also looked to Persia's ghetto-like melet system for guidance.

At various times, especially under comparatively secular caliphs, Islamic regimes did display more religious tolerance than Christian regimes, particularly toward Jews. But neither the Qur'an nor Islamic law, which are much more closely linked than the Bible and any past or present system of governance, ever sanctioned the fundamental equality that predicates modern tolerance.

One of the most popular verses in the Qur'an states, "There is no compulsion in religion" (2:258). Yet the Qur'an also mandates:

"Fight those who do not believe in Allah, nor in the latter day, nor do they prohibit what Allah and His Apostle have prohibited, nor follow the religion of truth, out of those who have been given the Book, until they pay the tax in acknowledgment of superiority and they are in a state of subjection" (9:29).

Umar's pact is thus not a peace treaty, but a description of the terms of his victory. Per the prophet's instructions, it prohibits what Allah prohibits (wine) and imposes a steep tax—failure to pay the poll tax (jizya) voided the contract. It also codifies Muslim superiority while humiliating anyone who clings to another religion.

Even some provisions that seem preferential undercut non-Muslim communities. For example, dhimmi were exempted from military service—and from the rich bonuses in pay and plunder that soldiers received. This placed dhimmi beneath mawali, recent Arab converts to Islam who were barred from some privileges but could serve in the military.

Despite the obvious incentives to convert, most Christians and Jews under early Muslim rule held onto their faith. But resistance eventually died out in all but a few pockets. The inability to build new places of worship or repair old ones, the prohibition on evangelism, and the fact that Muslim men could marry Christian and Jewish women (and raise their children as Muslims) while dhimmi could marry only their own kind achieved exactly what they were supposed to achieve. Islam won the region.

Elesha Coffman is managing editor of Christian History.