Around 50,000 members of the Yazidi community, many women and children, have been left trapped on Mount Sinjar in north west Iraq after they were driven into the mountains following threats from Islamic extremists in the area.

Predominantly ethnic Kurds, the Yazidis are one of Iraq's oldest minority communities. Historically misunderstood, they have never abandoned their beliefs despite centuries of widespread persecution.

The Yazidis live in small communities mainly scattered through north west Iraq, north west Syria and south east Turkey, although members are also found in Georgia and Armenia.

Accounts of their population vary, with estimates ranging from 50,000 to a million, and their number has fallen considerably over the past 100 years.

Despite this, they have a well-organised society, following a chief sheikh as their religious leader and an emir, or prince, as the secular head.

Their beliefs combine elements of a number of other religions, including Zoroastrianism, Judaism, Christianity and Islam.

Yazidis worship an angel figure, Malak Ta'us, or Peacock Angel, who is considered to be the devil by some Muslims and Christians, leading to the misconception that Yazidis are devil-worshippers and the cause of much of their persecution. Yazidis - who do not believe in hell or evil - deny they are.

Many Yazidi rituals centre on Sheikh Adi, a Sufi Arab who lived in northern Iraq in the 12th century and is considered the religion's chief saint. Pilgrims hold festivals near his tomb, north of Mosul.

Many Yazidi traditions are shrouded in such secrecy that most have never been witnessed by outsiders. Yazidis regard marriage outside their faith as a sin punishable by ostracism or even death to restore lost honour.

Most Yazidis, even young people, choose to live in their isolated communities, though they often face extreme poverty.

The Yazidis have been targeted before, and claim to have been subjected to 72 genocides during the Ottoman rule of the 18th and 19th centuries.

In 2007 a series of massive truck bombs in northern Iraq killed nearly 500 villagers from the group in August 2007.

Now, forced to flee after the Islamic State group gave them an ultimatum to convert to Islam, pay a religious fine, flee or face death, the plight of these secretive people is under the world's spotlight.