Huguenots were members of a French Protestant denomination known for their fierce critiques of the Roman Catholic Church and independent communities in southern and western France. When attacked by the Catholic church for being heretical, they defended themselves in a series of religious conflicts known as the French Wars of Religion, fought intermittently from 1562 to the early 17th century. Although they maintained their religious freedom for over a hundred years ten of thousands were killed by the Church and eventually, when Protestantism was declared illegal, most of those surviving emigrated from France to avoid forced conversion to Catholicism.

From Wikipedia:

Huguenot rebellions in the 1620s resulted in the abolition of their political and military privileges. They retained the religious provisions of the Edict of Nantes until the rule of Louis XIV, who gradually increased persecution of Protestantism until he issued the Edict of Fontainebleau(1685). This ended legal recognition of Protestantism in France and the Huguenots were forced either to convert to Catholicism (possibly as Nicodemites) or flee as refugees; they were subject to violent dragonnades. Louis XIV claimed that the French Huguenot population was reduced from about 800,000-900,000 adherents to just 1,000-1,500. He exaggerated the decline, but the dragonnades were devastating for the French Protestant community.

See Wikipedia’s entry on the Huguenots for more information!