Its most important early promoter was Al Hakim bi-Amrillah, the sixth leader of the Fatimid Caliphate that spanned a large area of North Africa and the Middle East and had its capital in Cairo. After his mysterious disappearance, his followers in Egypt were exterminated.
But they survived in other areas of the Middle East, including in present-day Lebanon and Syria.
In 1044, after a brief period of proselytization, the faith was closed to converts. Early Druze communities were insular and isolated and left historians with few records.
The religious texts have never been widely disseminated, leaving it to the sheiks to educate adherents on the finer points of the faith.
The diaspora began as a trickle and picked up in 1975 with the beginning of Lebanon's 15-year civil war. The country's 2006 war with Israel spurred more to leave, and most recently, many Druze have joined the stream of refugees from Syria's civil war.
As Druze members have branched out, many have lost touch with the religion, raising existential questions about its future.
"Very few of them have an in-depth understanding of their dogmas," said Chad Kassem Radwan, an anthropologist of Lebanese Druze descent who wrote a doctoral dissertation for the University of South Florida on Druze identity in Lebanon. "How do you preserve your heritage? This is truly the seminal issue of the Druze community."
He and most Druze who care give the same answer: marriage.
Marrying outside the faith is a betrayal that is not easily forgiven.
"Our children always ask me, 'Why do we have to marry a Druze? What if I fall in love with someone not Druze?' " said Anita Dakdouk, who was born into a Lebanese Druze family in Venezuela and now lives in Valencia , where she and her Druze husband run a coffee company. "I tell them, 'Don't think about yourself only, because there is family involved.' "