Formed in 1964 from the regiments of the East Anglian Brigade, which themselves had been formed through a series of amalgamations of six former County Regiments between 1958-60. Amalgamations at this time had been:
The Royal Norfolk Regiment with The Suffolk Regiment
(the latter including The Cambridgeshire Regiment),
The Royal Lincolnshire Regiment with The Northamptonshire Regiment
The Bedfordshire and Hertfordshire Regiment with The Essex Regiment.
The East Anglian Brigade comprised the 1st, 2nd and 3rd East Anglian Regiments
The Royal Leicestershire Regiment.
On 1 September 1964 the four regiments of The East Anglian Brigade became the four battalions of The Royal Anglian Regiment, the first Large Regiment of Infantry to be formed in the British Army. At the same time the Territorial Army battalions of the former regiments were affiliated to the Regiment, that is:
4th Battalion The Royal Norfolk Regiment (TA)
The Suffolk and Cambridgeshire Regiment (TA)
4th/6th Battalion The Royal Lincolnshire Regiment (TA)
1st Battalion The Bedfordshire and Hertfordshire Regiment (TA)
4th/5th Battalion The Essex Regiment (TA)
4th/5th Battalion The Royal Leicestershire Regiment (TA)
4th/5th Battalion The Northamptonshire Regiment (TA)
These Territorial Army battalions later formed The Royal Anglian Regiment's 5th(Volunteer) Battalion in 1967 and the 6th and 7th (Volunteer) Battalions in 1971. The four regular and three Territorial Army battalions were reduced to two regular battalions, the 1st and 2nd, and two Territorial Army battalions, the 6th and 7th(Volunteer) Battalions, by 1996.