The Order of the Carmelites were one of the great mendicant orders of the middle ages. The Carmelite order can be traced back to sometime in the 12th Century, although many claim an even older tradition dating back to Elijah in the Old Testament.
Mt. Carmel in Palestine was where, in the Old Testament, Elijah was supposed to have defended the God of Israel against the priests of Baal. Sometime in the 12th century, a group of pilgrims from Europe built a hermitage in Mt. Carmel, and dedicated themselves to worship God following the example of Elijah, and the Blessed Virgin Mary.
The Order was officially recognized by the Roman Catholic Church in 1222, by Pope Honorius III, who approved the Carmelite Rule, formulated by St. Albert, the Patriarch of Jerusalem. The Carmelites were forced to leave their original hermitage in Mt. Carmel when the Saracens recovered the Holy Land from the Crusaders.
In the middle ages, Confraternities of the Scapular of Our Lady of Mount Carmel were established throughout the world. As a symbol of unity with the Carmelites, these laity wore a small version of the brown scapular that Carmelite monks wore. This brown scapular has been thought of as a talisman that wards off evil, and sometimes even a promise of automatic entry to heaven once a person dies. The Carmelite Order officially denies that the scapular does these.
In the modern day, the Carmelites dedicate themselves to missionary work throughout the globe. Probably the most famous Carmelites are the two Thereses: St. Therese of Lisieux, and St. Teresa of Avila.