COLUMBUS, Ohio - Although most people think of slavery as a matter of racial oppression, new research has suggested that, between 1500 and 1800, human bondage was often based on religion rather than on race.
Long-running hostilities between Muslims and Christians in Europe, Africa, and the Middle East during these three centuries resulted in the enslavement of at least 3 million people of both faiths, according to Robert C. Davis, professor of history at Ohio State University.
Davis examined this "faith slavery" - a term he coined -- in his new book, Holy War and Human Bondage: Tales of Christian-Muslim Slavery in the Early-Modern Mediterranean (Praeger).
As a result of his research, Davis estimated that during these centuries more than 1 million Muslims were enslaved in Europe and another 2 million Christians suffered the same fate in North Africa and the Near East.
"Faith slavery had huge economic and social consequences at the time but most people today don't even know about it," Davis said.
Though we are familiar with the clash between Christianity and Islam today, in early-modern times the balance of forces was much different from what it is now, according to Davis.
"During this period, both sides, Muslims and Christians, had nearly equal power," Davis said. "It was really a clash of empires and taking slaves was part of the conflict."
If people today are familiar with faith slavery at all, it is because of novels and films about Muslim corsairs who used Christians as their galley slaves and about Turkish harems including Christian slave women.
But in reality Mediterranean slavery was much more extensive, and much more brutal, than these fictional versions might suggest, Davis says.
Muslim corsairs would capture ships and raid seaside towns in the Mediterranean and Atlantic, in search of men, women and children for slaves.
Once captured, men were made to row galleys, work in heavy construction, at stone quarries, or on private farms. Women were typically sold into harems, for either household or sexual duties.
But faith slavery went both ways: many thousands of Muslims were also captured and enslaved, in Italy, Spain, and Malta.
Davis first explored faith slavery in his 2004 book, Christian Slaves, Muslim Master: White Slavery in the Mediterranean, the Barbary Coast, and Italy, 1500-1800 (Palgrave MacMillian).
To calculate how many Europeans were enslaved on Africa's Barbary Coast, Davis developed a unique methodology in that book. Taking the best contemporary estimates of how many slaves were at each location at a given time, he then calculated how many new slaves it would take to replace the ones who died, escaped or were ransomed.
He felt that this is the best way available to make enslavement estimates, given the limited records.
In his new book, he expanded this research methodology to calculate how many Christians were enslaved in the Near East, as well as the extent of Islamic slavery in Christian Europe.
"Even rough calculations make it clear that Mediterranean faith slaving was not some minor phenomenon, a petty problem for people at the time, as has been assumed by many historians today," Davis said.
"Rather, it was a huge business and a vital part of the economy and the social fabric at the time."
Entire villages along the coast of Italy and Spain were abandoned after raids by Muslim corsairs, Davis said.
In addition, ransoming back a slave was expensive - a year's income or more for many Europeans.
"The sheer expense of getting their loved ones back represented an enormous transfer of wealth from Europe to Africa," he said (Muslim slaves were more rarely ransomed).
And while faith slaving was concentrated in the Mediterranean, its reach extended far beyond, Davis found.
In 1627, for instance, a corsair raid on Iceland brought about 400 Icelandic slaves to Algiers. Similar attacks were carried out in Ireland and all along the English coast in the 1630s and 1640s. Most of the captives died in slavery.
Nor was the United States immune. One of the many personal stories that Davis used to give a human face to the statistics is that of the American seaman John Foss. Captured by Algerian corsairs near Spain in 1793, Foss and his fellow crew members labored as slaves for two years before the fledgling American government finally ransomed them.
In his journal, Foss recalled how he, together with 130 fellow Americans and a thousand or more other slaves quarried and hauled enormous stone blocks under the overseers' lash.
Faith slavery was different in one significant way from the more familiar race slavery, Davis said. Faith slaves, both Christian and Muslim, could convert to their masters' religion.
For Christians, conversion to Islam was simple: all they had to do was swear there was one God, and his name was Allah.
But the results of their conversion were mixed. Though now Muslims, such "renegades" were still slaves, even if their masters usually gave them easier work. On the other hand, such converts had a much lower chance of being ransomed.
"A Muslim slave owner who let a Muslim slave be ransomed was essentially abandoning someone from the faith, which was punishable by death," Davis said.
Consequently, many Muslim slave owners didn't want their Christians slaves to convert. Davis told of one master who beat a would-be renegade until the slave recanted his conversion.
Given the historical magnitude and impact of faith slavery, Davis said he is often asked why more people don't know about it and why it isn't taught in schools.
Davis admitted he is not entirely sure. One reason, he said, may be that faith slavery "does not fit the historical master narrative that people in the United States and Europe tend to assume."
"This narrative holds that from Columbus' time until the 20th century, history was largely about European colonial expansion, with the imposition of white, European, Christian power on much of the world," Davis said.
"This story of faith slavery does not fit that narrative. The idea that triumphant Europeans were not everywhere inflicting their dominance on others seems counter-intuitive," Davis said.
"But in fact, during this centuries-long struggle between nearly equal empires, millions of European Christians ended up enslaved in Muslim hands."
Some historians have minimized faith slavery by calling victims "captives" rather than "slaves," as if they were simply prisoners of war. They argue that since some of those captured were eventually ransomed, they were never really slaves.
"That ignores the fact that more than half of the Christian slaves, and almost all of the Muslims, were never ransomed," Davis said.
Moreover, these faith slaves were treated very much like the more familiar African slaves, Davis said: made to work long days in difficult, dangerous jobs, poorly fed and brutally beaten.
"Some people assume that faith slavery, because it was not based on race, was less brutal or dehumanizing. Nothing could be further from the truth," he said.
"Just as with black Africans, faith slaves were considered commodities to be bought and sold. If anything, religious intolerance justified extremely cruel and harsh treatment of both Christian and Muslim slaves."
Davis noted that race slavery ensnared more victims than faith slavery. About 10 to 12 million black Africans were brought to the Americas as slaves, over three times the number he has calculated for Mediterranean faith slaves.
"But that shouldn't minimize the huge impact that 3 or 4 million faith slaves had on history."
Davis said he hopes his research encourages people to remember an historical reality that is often forgotten or ignored.
"Faith slavery played an important role in both American and European history. It deserves more attention," Davis said.
Yet Davis has taken issue with the argument that the slavery of white Europeans somehow mitigates or diminishes the enslavement of black Africans in the Americas.
"That doesn't make sense to me. Though faith and race slavery were both pervasive in these centuries, the enslavement of some white Christians can hardly balance the moral wrong of the slavery other whites inflicted on Africans," he said. "Two such enormous wrongs don't make anything right."