The Open Brethren form independent, autonomous assemblies and the name, "Open," is given to them to distinguish them from "Exclusive Brethren," with whom they share historical roots. The division of the Plymouth Brethren into the Open Brethren and Exclusive Brethren took place in 1848 and has been well documented. The Open Brethren are committed to missionary work and hold that the Holy Bible is the first authority in matters of faith and practice. Each assembly (or congregation) is independent of the others in doctrinal matters, yet there is a high degree of communication and cooperation between those who share similar doctrine and practice. Open Brethren assemblies vary from tight gatherings which only extend fellowship to those who have first left the denominations to very loose gatheri