Governance of the Methodist Church of Great Britain is based on the principle of connexionalism—a highly centralised structure. From its inception under John Wesley, Methodism has always laid strong emphasis on the interdependence and mutual support, in terms of ministry, mission and finance, of one local congregation for another. The Church community has never been seen in isolation either from its immediately neighbouring Church communities or from the centralised national organisation. Wesley himself journeyed around the country, preaching, evangelizing and establishing local worshipping communities, often under lay leadership. Soon these local communities of worshipping Christians formalised their relationships with neighbouring Methodist communities to create Circuits, and the Circuits and Churches contained within them, were from the very beginning 'connected' (hence the peculiarly Methodist concept of the 'Connexion') to the centre and Methodism's governing body, the annual Conference.
A Circuit is a group of Local Churches under the care of one or more ministers. The Circuit is the main functional unit of Methodism, in that a large number of activities are organised at this level. For example, ministers are appointed firstly to the Circuit and secondly to the pastoral care of Local Churches. Preaching appointments for both ministers and (lay) Local Preachers are organised by the Circuit and advertised on a "Preaching Plan" issued every three months by the leader of the Circuit, the Superintendent Minister. Upwards, Circuits are grouped into geographical Districts, headed a District Chair. Through the work of its annual conference and working parties the Methodist Church is also exploring the value of an organisational and operational tier 'larger than circuit' in sustaining its mission.
Methodist Churches which were established by British Missionaries are also modelled on the structure of the British Church.
The earliest preachers under John Wesley were itinerant, and preached around an area from a home base. "Circuit", or "Round" as they were first named, was therefore the natural name for the area they covered. At first they were named after their founder of main itinerant preacher. For example, 'John Bennet's Round', or the 'Circuit of William Darney's Societies'. The first official list dates from 1746.