Complex sentence: From 1974 to 1996 it was a local government district borough in the County of Avon but was merged on April 1,1996 with its neighbour Northavon to form South Gloucestershire.
Split into simpler sentences: From 1974 to 1996 it was a local government district borough in the County of Avon. It was merged on April 1,1996 with its neighborouging Northavon to form South Gloucestershire.