The Plymouth Brethren are a conservative, low church, nonconformist, Evangelical Christian movement whose history can be traced to Dublin, Ireland in the late 1820s, originating from Anglicanism. Among other beliefs, the group emphasizes sola scriptura, the belief that the Bible is the supreme authority for church doctrine and practice over and above any other source of authority.
Plymouth Brethren generally see themselves as a network of like-minded independent churches, not as a denomination. They would generally prefer that their gatherings be referred to as "assemblies" rather than "churches" but, in the interests of simplicity, this article uses both terms interchangeably.
An influential figure among the early Plymouth Brethren was John Nelson Darby (1800–82). The movement refused to take any denominational name to itself, a stance that some still maintain. The title "The Brethren," however, is one that many of their number are comfortable with, in that the Bible designates all believers as "brethren": "one is your Master, even Christ; and all ye are brethren" (Matthew 23:8; Greek: ἀδελφοί, adelphoi).
Brethren assemblies (as their gatherings are most often called) are divided into two major branches: the Open Brethren and the Exclusive Brethren, following a schism that took place in 1848. Both of these main branches are themselves divided into several smaller streams, with varying degrees of communication and overlap among them. (The general category "Exclusive Brethren" has been confused in the media with a much smaller group known as the Plymouth Brethren Christian Church (PBCC) or the Raven-Taylor-Hales Brethren, numbering only around 40,000 worldwide.)