The Christadelphian community in the United Kingdom effectively dates from Thomas's first lecturing tour (May 1848 – October 1850). His message was particularly welcomed in Scotland, and Campbellite, Unitarian and Adventist friends separated to form groups of "Baptised Believers". Two thirds of ecclesias, and members, in Britain before 1864 were in Scotland. In 1849, during his tour of Britain, he completed (a decade and a half before the name "Christadelphian" was conceived) "Elpis Israel" in which he laid out his understanding of the main doctrines of the Bible. Since his medium for bringing change was print and debate, it was natural for the origins of the Christadelphian body to be associated with books and journals, such as Thomas's "Herald of the Kingdom".