It was originally formed as a Poor Law Union on 5 April 1836 with 26 Guardians representing the 21 parishes in the Union[1] and the Guardians of the Poor became the Rural Sanitary Authority for the District in 1872.
In 1930 the Guardians were abolished when their functions were transferred to the Rural District Council.
The arms of the Council featured a "Thorn-berry" tree for Thornbury and a pair of gold wings for the important aircraft industry at Filton and Patchway.
[3] It was abolished in 1974 and the majority of it transferred into the new county of Avon, as part of the new district of Northavon.
The records of Thornbury RDC between 1872 and 1974 are held at Gloucestershire Archives in Gloucester, ref.