The Yazidis (Yezidis) live principally in Northern Iraq. There are approximately one million people worldwide.
Historically, the Yazidis lived primarily in communities in locales that are in present-day Iraq, Syria, and Turkey, and also had significant numbers in Armenia and Georgia. However, events since the 20th century have resulted in considerable demographic shift in these areas as well as mass emigration. As a result, population estimates are unclear in many regions, and estimates of the size of the total population vary.
The bulk of the Yazidi population lives in Iraq, where they make up an important minority community. Estimates of the size is about 500,000. They are particularly concentrated in northern Iraq in the Nineveh Province. The two biggest communities are in Shekhan, northeast of Mosul, and in Sinjar, at the Syrian border 80 kilometres (50 mi) west of Mosul.
In Shekhan is the shrine of Sheikh Adi ibn Musafir at Lalish. During the 20th century, the Shekhan community struggled for dominance with the more conservative Sinjar community.
Yazidis in Syria live primarily in two communities, one in the Al-Jazira area and the other in the Kurd-Dagh. Population numbers for the Syrian Yazidi community are unclear. In 1963, the community was estimated at about 10,000, according to the national census, but numbers for 1987 were unavailable. There may be between about 12,000 and 15,000 Yazidis in Syria today, though more than half of the community may have emigrated from Syria since the 1980s.
The Yazidi People
The Yazidis have a rich spiritual tradition that has elements of ancient Mesopotamian religions and similarities with Christianity, Judaism and Islam. They can trace back their religious calendar 6764 years, thus making 2008 CE the Yazidi year of 6764. 
Source: Yazidis International (link to English website)
Below you see the refugee camp Sharya where Layla lives