While other religious groups of the period faded away with time, Fox devoted himself in 1666–1668 to setting up a structure of meetings which has remained virtually the same up until the present day: local 'particular' meetings, grouped regionally into "monthly meetings", "quarterly meetings" above them, and an annual "General Assembly of the Brethren" (usually referred to as a Yearly Meeting) as the leading authority. There has been a national annual meeting of some sort in Britain every year since 1668.