The 5th Battalion Prince of Wales's Volunteers (South Lancashire Regiment) was reformed at St Helens in 1920, with Lt-Col W.N. Pilkington, DSO and Bar, in command and Maj Guy Pilkington, DSO, as second-in-command.
In the 1930s the increasing need for anti-aircraft (AA) defence for Britain's cities was addressed by converting a number of TA infantry battalions into searchlight (S/L) regiments.