Members of the Yazidi sect in their refugee camp in Iraq. (Photo: AFP/Getty)
They are scared of lettuce. They abhor pumpkins. They practise maybe the oldest religion in the world. And now, after at least 6,000 years, they are finally being exterminated, even as I write this.
If you haven't noticed this epochal crime – the raping and the slaughter – you're not alone. Of late, the world has focused on the horrors of Gaza. When we've had time to acknowledge the Satanic cruelties of Isis, in Iraq, we've looked to the barbaric treatment of women, and Christians. Yet the genocide of the Yazidi, by Isis, is as evil as anything going on right now in the Middle East; it is also uniquely destructive of a remarkable cultural survival.
So who are the Yazidi? Some years ago I studied them when researching a thriller. I also traveled to meet their small diaspora community, in Celle, north Germany. And what I found was astonishing.
Yazidism is much older than Islam, and much older than Christianity. It is also deeply peculiar. The Yazidi honour sacred trees. Women must not cut their hair. Marriage is forbidden in April. They avoid wearing dark blue because it is "too holy".
They are divided strictly into castes, who cannot marry each other. The upper castes are polygamous. Anyone of the faith who marries a non-Yazidi risks ostracism, or worse. Yazidism is syncretistic: it combines elements of many faiths. Like Hindus, they believe in reincarnation. Like ancient Mithraists, they sacrifice bulls. They practise baptism, like Christians. When they pray, they face the sun – like Zoroastrians. There are also strong links with Sufism, the mystical branch of Islam.
Then there is the devil worship: arguably, the Yazidi worship what Christians or Muslims might call "Satan", though the Yazidi call him "Melek Taus", and he appears in the form of a peacock angel.
Why might Melek Taus be "the devil"? For a start, the Yazidi believe the peacock angel led a rebellion in heaven: clearly echoing the story of Lucifer, cast into Hell by the Christian God. Also, the very word "Melek" is cognate with "Moloch", the name of a Biblical demon – who demanded human sacrifice.
The avian imagery of Melek Taus likewise indicates a demonic aspect. The Yazidi come from the ancient lands of Sumeria and Assyria, in modern-day Turkey, Iraq and Kurdistan. Sumerian gods were often cruel, and equipped with beaks and wings. Birdlike. Three thousand years ago the Assyrians worshipped flying demons, spirits of the desert wind. One was the scaly-winged demon in The Exorcist: Pazuzu.
The Yazidi reverence for birds – and snakes – also appears to be extremely old. Excavations at ancient Catalhoyuk, in Turkey, show that the people there revered bird-gods as long ago as 7000BC. Even older is Gobekli Tepe, a megalithic site near Sanliurfa, in Kurdish Turkey (Sanliurfa was once a stronghold of Yazidism). The extraordinary temple of Gobekli Tepe boasts carvings of winged birdmen, and images of buzzards and serpents.
Taking all this evidence into account, a fair guess is that Yazidism is a vastly ancient form of bird-worship, that could date back 6,000 years or more. If this is right, it means that Yazidism is therefore the Ur-religion, the mother ship of Middle Eastern faiths, and it is us who have incorporated Yazidi myths and beliefs into our religions, of Christianity and Islam and Judaism.
And now, in the dusty cities of northern Iraq, Yazidism is finally dying. Moloch has returned to devour the gentle and peaceful Yazidi people, in the form of hateful, virulent, sadistic Islamism. Put it another way, the devil has revealed a sense of irony, even as the rest of us sit back, and passively watch the most ancient culture in the world being erased from human history.
• Get the latest comment and analysis from the Telegraph