Plymouth Brethren, founded by John Nelson Darby, was a splintered Christian sect that broke from the Church of England originally formed in Dublin in 1829 and in Plymouth in 1831. Members were strict fundamentalists, considering themselves ‘true Christians.’ Most reject the name Plymouth, preferring to be called Brethren or Christian Brethren so not to denote a denomination, although several exist.
There was a separation into two main groups: the Open Brethren and the Exclusive Brethren, the latter has splintered into several groups.
The special interest in this sect is that Aleister Crowley’s parents and family were members. His father was a Brethren preacher. As a child Crowley helped his father preach but after his father’s death, and the harsh treatment he received from his mother who called him ‘the Beast’ and uncle Crowley rebelled against the sect and Christianity. A.G.H.
Bowker, John, The Oxford Dictionary of World Religions, New York, Oxford University Press, 1997, p. 756