The Iraqi mountain community that U.S. President Barack Obama is racing to defend numbers in the tens or hundreds of thousands, with roots in the 12th century and a history of persecution.
The previously obscure group is spread across northern Iraq, Syria and Turkey, and its members follow an unorthodox blend of Islam, Christianity and ancient Zoroastrianism, one reason they're being targeted by Sunni militants from the Islamic State.
The Yazidis are ethnic Kurds whose faith was founded by a 12th-century sheikh, borrowing from the pre-Islamic Persian religion of Zoroastrianism as well as Christianity and Islam. The Yazidis believe in reincarnation, and perform baptisms with consecrated water as well as circumcisions and animal sacrifices, according to a study by Christine Allison, professor of Kurdish studies at Exeter University in southwestern England.