In 1974 the non-metropolitan county of Shropshire was constituted, covering the entire county. There was a two-tier system of local government, constituting a county council (as the upper tier) and six district councils - Bridgnorth, North Shropshire, Oswestry, Shrewsbury and Atcham, South Shropshire and The Wrekin. In 1998 The Wrekin became a unitary authority, administratively separate from the county council, and became Telford and Wrekin. The two-tier structure remained in the remainder of the county and was the least populated two-tier area in England.