In the moments before he raped the 12-year-old girl, the Islamic State fighter took the time to explain that what he was about to do was not a sin. Because the pre-teen girl practised a religion other than Islam, the Koran not only gave him the right to rape her – it condoned and encouraged it, he insisted.

He bound her hands and gagged her. Then he knelt beside the bed and prostrated himself in prayer before getting on top of her. When it was over, he knelt to pray again, bookending the rape with acts of religious devotion. “I kept telling him it hurts – please stop,” said the girl, whose body is so small an adult could circle her waist with two hands.

“He told me that according to Islam he is allowed to rape an unbeliever. He said that by raping me, he is drawing closer to God,” she said in an interview alongside her family in a refugee camp in Qadiya, Iraq, to which she escaped after 11 months of captivity.

The systematic rape of women and girls from the Yazidi religious minority has become deeply enmeshed in the organisation and the radical theology of Islamic State in the year since the group announced it was reviving slavery as an institution. Interviews with 21 women and girls who recently escaped Islamic State, as well as an examination of the group’s official communications, illuminate how the practice has been enshrined in the group’s core tenets.

The trade in Yazidi women and girls has created a persistent infrastructure, with a network of warehouses where the victims are held, viewing rooms where they are inspected and marketed, and a dedicated fleet of buses used to transport them.

A total of 5,270 Yazidis were abducted last year, and at least 3,144 are still being held, according to community leaders. To handle them, Islamic State has developed a detailed bureaucracy of sex slavery, including sales contracts notarised by IS-run Islamic courts. And the practice has become an established recruiting tool to lure men from deeply conservative Muslim societies, where casual sex is taboo and dating is forbidden.

A growing body of internal policy memos and theological discussions has established guidelines for slavery, including a lengthy how-to manual issued by the Islamic State Research and Fatwa Department just last month. Repeatedly, the Islamic State leadership has emphasised a narrow and selective reading of the Koran and other religious rulings to not only justify violence, but also to elevate and celebrate each sexual assault as spiritually beneficial, even virtuous.

“Every time that he came to rape me, he would pray,” said F, a 15-year-old girl who was captured on the shoulder of Mount Sinjar one year ago and was sold to an Iraqi fighter in his 20s. Like some others interviewed by the New York Times, she wanted to be identified only by her first initial because of the shame associated with rape.

“He kept telling me this is ibadah,” she said, using a term from Islamic scripture meaning worship. “He said that raping me is his prayer to God. I said to him, ‘What you’re doing to me is wrong, and it will not bring you closer to God.’ And he said, ‘No, it’s allowed. It’s halal,’” said the teenager, who escaped in April with the help of smugglers after being enslaved for nearly nine months.

Calculated conquest

Islamic State’s formal introduction of systematic sexual slavery dates to August 3rd, 2014, when its fighters invaded the villages on the southern flank of Mount Sinjar, a craggy massif of dun-colored rock in northern Iraq. Its valleys and ravines are home to the Yazidis, a tiny religious minority who represent less than 1.5 percent of Iraq’s estimated population of 34 million. The offensive on the mountain came just two months after the fall of Mosul, the second-largest city in Iraq. At first, it appeared that the subsequent advance on the mountain was just another attempt to extend the territory controlled by Islamic State fighters.

Almost immediately, there were signs that their aim this time was different. Survivors say that men and women were separated within the first hour of their capture. Adolescent boys were told to lift up their shirts, and if they had armpit hair, they were directed to join their older brothers and fathers. In village after village, the men and older boys were driven or marched to nearby fields, where they were forced to lie down in the dirt and sprayed with automatic fire.

The women, girls and children, however, were hauled off in open-bed trucks. “The offensive on the mountain was as much a sexual conquest as it was for territorial gain,” said Matthew Barber, a University of Chicago expert on the Yazidi minority. He was in Dohuk, near Mount Sinjar, when the onslaught began last summer and helped create a foundation that provides psychological support for the escapees, who number more than 2,000, according to community activists.

Fifteen-year-old F says her family of nine was trying to escape, speeding up mountain switchbacks, when their aging Opel overheated. She, her mother, and her sisters – 14, 7, and four years old – were helplessly standing by their stalled car when a convoy of heavily armed Islamic State fighters encircled them.

“Right away, the fighters separated the men from the women,” she said. She, her mother and sisters were first taken in trucks to the nearest town on Mount Sinjar. “There, they separated me from my mom. The young, unmarried girls were forced to get into buses.”

The buses were white, with a painted stripe next to the word “Hajj,” suggesting that Islamic State had commandeered Iraqi government buses used to transport pilgrims for the annual pilgrimage to Mecca. So many Yazidi women and girls were loaded inside F’s bus that they were forced to sit on each other’s laps, she said.

Once the bus headed out, they noticed that the windows were blocked with curtains, an accouterment that appeared to have been added because the fighters planned to transport large numbers of women who were not covered in burqas or head scarves.

F’s account, including the physical description of the bus, the placement of the curtains and the manner in which the women were transported, is echoed by a dozen other female victims interviewed for this article. They described a similar set of circumstances even though they were kidnapped on different days and in locations miles apart.

F says she was driven to the Iraqi city of Mosul about six hours away, where they herded them into the Galaxy Wedding Hall. Other groups of women and girls were taken to a palace from the Saddam Hussein era, the Badoosh prison compound and the Directory of Youth building in Mosul, recent escapees said. And in addition to Mosul, women were herded into elementary schools and municipal buildings in the Iraqi towns of Tal Afar, Solah, Ba’aj and Sinjar City.

They would be held in confinement, some for days, some for months. Then, inevitably, they were loaded into the same fleet of buses again before being sent in smaller groups to Syria or to other locations inside Iraq, where they were bought and sold for sex.

“It was 100 per cent preplanned,” said Khider Domle, a Yazidi community activist who maintains a detailed database of the victims. “I spoke by telephone to the first family who arrived at the Directory of Youth in Mosul, and the hall was already prepared for them. They had mattresses, plates and utensils, food and water for hundreds of people.”

Detailed reports by Human Rights Watch and Amnesty International reach the same conclusion about the organised nature of the sex trade. In each location, survivors say Islamic State fighters first conducted a census of their female captives. Inside the voluminous Galaxy banquet hall, F sat on the marble floor, squeezed between other adolescent girls. In all, she estimates there were more than 1,300 Yazidi girls sitting, crouching, splayed out and leaning against the walls of the ballroom, a number that is confirmed by several other women held in the same location.

They each described how three Islamic State fighters walked in, holding a register. They told the girls to stand. Each one was instructed to state her first, middle and last name, her age, her home town, whether she was married, and if she had children.

For two months, F was held inside the Galaxy hall. Then one day, they came and began removing young women. Those who refused were dragged out by their hair, she said. In the parking lot the same fleet of Hajj buses was waiting to take them to their next destination, said F. Along with 24 other girls and young women, the 15-year-old was driven to an army base in Iraq. It was there in the parking lot that she heard the word “sabaya” for the first time.

“They laughed and jeered at us, saying ‘You are our sabaya.’ I didn’t know what that word meant,” she said. Later on, the local Islamic State leader explained it meant slave.

The market

Months later, Islamic State made clear in its online magazine that its campaign of enslaving Yazidi women and girls had been extensively preplanned. “Prior to the taking of Sinjar, Sharia students in the Islamic State were tasked to research the Yazidis,” said the English-language article, headlined “The Revival of Slavery Before the Hour,” which appeared in the October issue of Dabiq.

The article made clear that for the Yazidis, there was no chance to pay a tax known as jizya to be set free, “unlike the Jews and Christians”. “After capture, the Yazidi women and children were then divided according to the Sharia among the fighters of the Islamic State who participated in the Sinjar operations, after one fifth of the slaves were transferred to the Islamic State’s authority to be divided” as spoils, the article said.

In much the same way as specific Bible passages were used centuries later to support the slave trade in the United States, Islamic State cites specific verses or stories in the Koran or else in the Sunna, the traditions based on the sayings and deeds of the Prophet Muhammad, to justify their human trafficking, experts say.

Scholars of Islamic theology disagree, however, on the proper interpretation of these verses, and on the divisive question of whether Islam actually sanctions slavery. Many argue that slavery figures in Islamic scripture in much the same way that it figures in the Bible – as a reflection of the period in antiquity in which the religion was born.

“In the milieu in which the Koran arose, there was a widespread practice of men having sexual relationships with unfree women,” said Kecia Ali, an associate professor of religion at Boston University and the author of a book on slavery in early Islam. “It wasn’t a particular religious institution. It was just how people did things.”

Cole Bunzel, a scholar of Islamic theology at Princeton University, disagrees, pointing to the numerous references to the phrase “Those your right hand possesses” in the Koran, which for centuries has been interpreted to mean female slaves. He also points to the corpus of Islamic jurisprudence, which continues into the modern era and which he says includes detailed rules for the treatment of slaves.

“There is a great deal of scripture that sanctions slavery,” said Bunzel, the author of a research paper published by the Brookings Institution on the ideology of Islamic State. “You can argue that it is no longer relevant and has fallen into abeyance. Isis [Islamic State] would argue that these institutions need to be revived, because that is what the Prophet and his companions did.”

Buildings where the women were collected and held sometimes included a viewing room. “When they put us in the building, they said we had arrived at the ‘Sabaya Market,’” said one 19-year-old victim, whose first initial is I. “I understood we were now in a slave market.” She estimated there were at least 500 other unmarried women and girls in the multistory building, with the youngest among them being 11.

When the buyers arrived, the girls were taken one by one into a separate room. “The emirs sat against the wall and called us by name. We had to sit in a chair facing them. You had to look at them, and before you went in, they took away our scarves and anything we could have used to cover ourselves,” she said. “When it was my turn, they made me stand four times. They made me turn around.”

The captives were also forced to answer intimate questions, including reporting the exact date of their last menstrual cycle. They realized that the fighters were trying to determine whether they were pregnant, in keeping with a Sharia rule stating that a man cannot have intercourse with his slave if she is pregnant.

Property of Islamic State

The use of sex slavery by Islamic State initially surprised even the group’s most ardent supporters; many of whom sparred with journalists online after the first reports of systematic rape. Islamic State’s leadership has repeatedly sought to justify the practice to its internal audience. After the initial article in Dabiq in October, the issue came up in the publication again this year, in an editorial in May that expressed the writer’s hurt and dismay at the fact that some of the group’s own sympathisers had questioned the institution of slavery.

“What really alarmed me was that some of the Islamic State’s supporters started denying the matter as if the soldiers of the Khilafah had committed a mistake or evil,” the author wrote. “I write this while the letters drip of pride,’’ he said. “We have indeed raided and captured the kafirahwomen and drove them like sheep by the edge of the sword.” “Kafirah” refers to infidels.

In a pamphlet published online in December, the Research and Fatwa Department of Islamic State detailed best practices, including explaining that slaves belong to the estate of the fighter who bought them and therefore can be willed to another man and disposed of just like any other property after his death.

Recent escapees describe an intricate bureaucracy surrounding their captivity, with their status as a slave registered in a contract. When their owner would sell them to another buyer, a new contract would be drafted, like transferring a property deed. At the same time, slaves can also be set free, and fighters are promised a heavenly reward for doing so.

Though rare, this has created one avenue of escape for victims. A 25-year-old victim who escaped last month, identified by her first initial, A, described how one day her Libyan master handed her a laminated piece of paper. He explained that he had finished his training as a suicide bomber and was planning to blow himself up, and was therefore setting her free.

Labelled a “Certificate of Emancipation,” the document was signed by the judge of the western province of Islamic State. The Yazidi woman presented it at security checkpoints as she left Syria to return to Iraq, where she rejoined her family in July.

Islamic State recently made it clear that sex with Christian and Jewish women captured in battle is also permissible, according to a new 34-page manual issued this summer by the terror group’s Research and Fatwa Department.

Just about the only prohibition is having sex with a pregnant slave, and the manual describes how an owner must wait for a female captive to have her menstruating cycle, in order to “make sure there is nothing in her womb”, before having intercourse with her. Of the 21 women and girls interviewed for this article, among the only ones who had not been raped were the women who were already pregnant at the moment of their capture, as well as those who were past menopause.

Beyond that, there appears to be no bounds to what is sexually permissible. Child rape is explicitly condoned: “It is permissible to have intercourse with the female slave who hasn’t reached puberty, if she is fit for intercourse,” according to a translation by the Middle East Media Research Institute of a pamphlet published on Twitter in December.

One 34-year-old Yazidi woman, who was bought and repeatedly raped by a Saudi fighter in the Syrian city of Shadadi, described how she fared better than the second slave in the household – a 12-year-old girl who was raped for days on end despite heavy bleeding.

“He destroyed her body. She was badly infected. The fighter kept coming and asking me, ‘Why does she smell so bad?’ And I said, she has an infection on the inside, you need to take care of her,” the woman said. Unmoved, he ignored the girl’s agony, continuing the ritual of praying before and after raping the child. “I said to him, ‘She’s just a little girl,’” the older woman recalled. “And he answered: ‘No. She’s not a little girl. She’s a slave. And she knows exactly how to have sex.’’’ “And having sex with her pleases God,” he said.

New York Times