How many Yazidis are there? If you’re talking about a genocide, you must first quantify the genus. The U.S. Department of State’s Bureau of Democracy, Human Rights, and Labor reported in 2012, based on the estimations of community leaders, that anywhere between 500,000 and 700,000 Yazidis reside in northern Iraq. The latest available Iraqi census mentioning the Yazidis dates back to 1965; it identifies the Yazidis as being 1 percent of the population, or 70,000. If that percentage held solid, there would be about 300,000 Yazidis living in Iraq today. In 2011, the International Organization for Migration estimated that about 230,000 Yazidis lived in the Sinjar district, home to the majority of the Yazidi population. Every time you try to count the Yazidis, their number seems to dwindle. This is true everywhere, but particularly on Mount Sinjar, where 30,000 Yazidis are stranded, surrounded by the murderous jihadis of the Islamic State, counting on Western aid and American air strikes if they are to survive.Where do the Yazidis live? In northern Iraq, mainly. Some in Syria. There were many Yazidis in Turkey as well, but in the early 20th century, when the Armenians fled a genocide of their own, many Yazidis took them in, which angered the Turks and led to a massive flight of Yazidi refugees. Some found shelter in Georgia, Armenia, and Russia. Many ended up in Germany, but there are small Yazidi diasporas across the world: in Sweden and in Denmark, in Belgium and in France and in Switzerland, in the United States and in Canada, in Australia, no more, probably, than 5,000 people in total.What are the origins of the Yazidis? They are fogged by time and legend. In the 12th century, Kurdish followers of the Sufi Sheikh Adi began deviating from Islam and adopting instead a host of local traditions, some Mesopotamian and Assyrian, some Zoroastrian and ancient Iranian, some Christian, some pagan. Once, their influence was considerable, but persecutions and conversions left the Yazidis depleted of strength and dwindled in numbers.What do the Yazidis believe? In one God, who sent seven divine beings to watch over us, the most formidable of which was Melek Taus, or the Peacock King. When Adam was created from dust, God ordered all his angels to bow before the lowly creature; six angels prostrated, but the Peacock King refused. He, the angel told God, was created from a spark of the Divine illumination, while the newcomer Adam was a creature of the earth. To the Yazidis, the lord’s order was a test, one that Melek Taus had passed by displaying fealty to God’s true spirit. As the Peacock King once contemplated right and wrong, the Yazidis believe, so do we on earth, and we have the magnificent archangel to look to when our spirit goes astray. The neighbors of the Yazidis did not see it this way. To them, Melek Taus was just another name for Lucifer, Shayatan, Satan, a rebellious being, a pure evil. They labeled the Yazidis “devil worshippers,” and some Western travelers who encountered the Yazidis in the late 19th and early 20th centuries applied the same label.Why did the belief that they are “devil worshippers” gain traction? Because the Yazidis did not mix with others. Because they married only their kind. Because they practiced a religion based largely on oral law. Because they observed a strict priestly hierarchy and depended on religious authorities to pass down judgments. Because they gravitated to their own places of pilgrimage. Because they kept their own calendar. Because they believed that the gates of heaven open each new year’s eve, and Melek Taus looks down at his charges, deciding who shall live and who shall perish.Did the hatred directed against the Yazidis subside? Never for long. Under Saddam Hussein, they were forcibly relocated to collective villages and subjected to “Arabization,” encouraging them to abandon their language and their creed. After the dictator’s fall, they fared no better: On Aug. 14, 2007, a coordinated attack involving four truck bombs claimed the lives of at least 500 Yazidis in two villages, wounding more than 1,500. It was the second-deadliest terrorist attack in the history of mankind; the brutalities of 9/11 were first.Where are the Yazidis now? As is well-known, more than 30,000 of them cower on Mount Sinjar, where they had sought shelter 10 days ago, fleeing the jihadis of the Islamic State. One woman told reporters she got a mountain goat to suckle her two-month-old after her own breast milk had run out. Other parents slashed their palms and offer their children the only liquid at their disposal, their blood. The temperature on Mount Sinjar exceeds 100 degrees Fahrenheit. Many have died, some, aware of the fate that awaits them should they fall captive, by their own hand.What is to be done? Humanitarian help is a start. So are air strikes. A more fleshed-out military mission would be a blessing. But these mark not the end of human solidarity, but its beginning. We owe the Yazidis more than our arms. We owe them our grief and our rage and our attention, all of which stem from a shared sense of destiny that all who had ever been persecuted forever feel.In the 19th century, travelers inquiring after the Yazidis uncovered a poem titled “This is the eulogy of Sheikh Adi; Upon him be peace!” and written in Arabic. “Mine are all existences together,” it read. “They are my gift and under my direction. And I am he that possesseth all majesty, and beneficence and charity are from my grace. And I am he that entereth the heart in my zeal.” There’s wisdom in these ancient lines, and room for zeal in our hearts yet.***You can help support Tablet’s unique brand of Jewish journalism. Click here to donate today.Liel Leibovitz is a senior writer for Tablet Magazine and a host of the Unorthodox podcast.