By 1632, Barebone had joined the semi-separatist congregation founded in 1616 by Henry Jacob, later to be led by John Lathrop and then, from 1637, by Henry Jessey. By December 1641 he had begun preaching to audiences at his premises at the Lock and Key, at the lower end of Fleet Street near Fetter Lane. On 19 December of that year, his sermon against bishops and the "Book of Common Prayer" attracted hostile attention from apprentices, who smashed the premises's windows.