For Iraq's small and secretive Yazidis community, Tuesday's attack was one of the worst massacres in the living memory of a community that believes they were the first people God created.
"We want the world to know us better," the sheikh known as the Prince of the Yazidis told me in northern Iraq well before the war when his diminishing community decided that they could no longer afford to be known as devil worshippers.
That label is believed to be part of the reason for the simultaneous suicide bombs that have killed 250 people - many of them women and children - in what will likely be deadliest suicide attack since the war began. Officials say the Yazidis, members of a secret pre-Islamic religion considered infidels by fundamentalist Muslims, received letters from al-Qaida in Iraq telling them to leave.
There are likely fewer than a million Yazidis in the world - by some estimates as few as 400,000. They are believed to be ethnically Kurds but they don't consider themselves Kurdish. Almost half of the entire community has become refugees in Germany and other parts of Europe.
They've been persecuted for centuries because they're mistakenly considered by many Muslims to be devil worshipers - a perception fueled by the secrecy of their ancient religion.
Visiting traditional Yazidis communities is like stepping into another world. Their temples-have cone-shaped roofs - the same shape as the wool felt hats worn by religious elders, who wear locks of hair in long braids. The ceremonies include elements of Zoroastroanism, the ancient Persian religion, and include the worship of fire and sun. At a temple in the Sinjar Mountains before the war, I watched the keeper of the temple light an oil lamp with four wicks and pray to each direction of the flame. In one of the temples, there was an etching of a serpent – in another the moon and the stars.
Like the religion, the temples are often hidden. The Yazidis elders have long worried that as young people become assimilated into Western culture, their religion could essentially disappear. It's an unforgiving faith - Yazidis are only allowed to marry other Yazidis.
In April, police say, members of one Yazidi community stoned to death a teenage Yazidi girl who had converted to Islam to marry a Muslim. Dozens of Yazidis were killed by Muslim extremists in retaliation.
In northern Iraq a few years ago, the "Prince of the Yazidis" a sheikh who spends his time in Germany when he's not in northern Iraq, told me they had decided that they could no longer be as secretive - that they had to persuade the world that they were God-fearing people. They translated their secret "black book" and even opened some of their ceremonies to outsiders.
Still, every time I asked what they believed I got somewhat different answers. While they had decided they needed to make their secret religion less secret, some were not so convinced.
I watched a ceremony in a village in the Sinjar Mountains surrounding a brass peacock - one of the seven the Yazidis believed God handed the first Yazidis directly - a representation of the archangel Michael in his form as the peacock angel. It's an oral tradition in which many of the rituals and beliefs are entrusted only to males - and only when they come of age. But one thing they firmly believe is that they were the first men.
Even more than most religions, they have a complicated relationship with God - the bottom line is that they know God is forgiving but Satan is not - and while they don't worship him, they make clear that they respect his power. So much so that Yazidis don't ever say his name or utter words starting with the letters 'sh' - the same sound that begins the word for Satan. They also don't wear the color blue, eat lettuce or wear ties with collars - all going back to their beliefs about the fallen angel to whom they pay homage.
"Science is our enemy," one of the elders told me. In some of the most traditional of Yazidi communities, education is discouraged. A 14-year-old girl in one village I went to told me she'd never been to school. It was considered "shameful" for girls to be educated, she said.
They've been persecuted for centuries and in times of trouble they retreat to the mountains and the caves. During the war near Dohuk, close to the Turkish border, when I was looking for Yazidi communities,
I found some had literally moved underground - in caves underneath villages that had been leveled by Saddam Hussein's forces during his attacks against the Kurds.
Under Saddam Hussein they survived by not making waves. Saddam, whose
Baath party was originally secular, didn't care what religion they were as long as they weren't a threat to him. Now there's a new threat to these people practicing a religion they believe is as old as man.