The district was formed in 1974 under the Local Government Act 1972. It covered parts of six former districts which were abolished at the same time, and was initially arranged into nine communities based on the former districts:
New Tredegar, covering the Aberbargoed, Cwmsyfiog, New Tredegar, and Phillipstown wards from Bedwellty Urban District (the rest of which went to Islwyn)
The first election to the council was held in 1973, initially operating as a shadow authority before coming into its powers on 1 April 1974. Political control of the council from 1974 until its abolition in 1996 was held by the following parties:[6]
The district council inherited the municipal bus fleets of Bedwas and Machen, Caerphilly and Gelligaer urban district councils. The united operation was given a dark brown, cream and gold livery, and ran operations throughout the valley and into Merthyr Tydfil and Newport.
With bus deregulation in 1986 the buses passed to Inter Valley Link Limited, owned by the district council at "arms length". Competition was very strong in the South Wales Valleys, and Inter Valley Link was sold to National Welsh Omnibus Services on 21 March 1989. National Welsh subsequently went into receivership in 1991.
Premises
The council inherited various offices from its predecessor authorities. It consolidated its premises in 1983 at Ystrad Fawr House at Ystrad Mynach, a Victorian house which had previously served as offices for the National Coal Board.[7][8][9] Ystrad Fawr continued to be used by the successor Caerphilly County Borough Council until 2008 when it was demolished to make way for the Ysbyty Ystrad Fawr hospital.