The Exclusive Brethren are a subset of the Christian evangelical movement generally described as the Plymouth Brethren. They are distinguished from the Open Brethren from whom they separated in 1848.
The Exclusive Brethren are now divided into a number of groups, most of which differ on minor points of doctrine or practice. Perhaps the best-known of these, mainly through media attention, is the Raven-Taylor-Hales group, now known as the Plymouth Brethren Christian Church, which maintains the doctrine of uncompromising separation from the world based on their interpretation of 2 Corinthians 6 and 2 Timothy 2, believing that attendance at the Communion Service, the ‘Lord’s Supper’, governs and strictly limits their relationship with others, even other Brethren groups.
These brethren have one fellowship in some nineteen countries — including France, Germany, Spain, Italy, Denmark, the Netherlands, Switzerland, Sweden, and Argentina, but they are more numerous in Australia, New Zealand, the United Kingdom, and North America where they are referred to just as the Exclusive Brethren or Brethren. Wikipedia: https://en.wikipedia.org/wiki/Exclusive_Brethren