What is a follower of Donatus, the leader of a body of North African schismatics and purists, who greatly disturbed the church in the 4th century. They claimed to be the true church called?

donatist — A follower of Donatus, the leader of a body of North African schismatics and purists, who greatly disturbed the church in the 4th century. They claimed to be the true church. (Webster's 1913.)