With the continued expansion of the TA's air defences, 320th (Dundee) Company and 319th (Aberdeen) Company combined with a newly raised battery at Cowdenbeath in 1938 to form 51st (Highland) AA Battalion, RE [REF].
In February 1942, the regiment was converted to the Light Anti-Aircraft (LAA) artillery role as 124 (Highland) Light Anti-Aircraft Regiment, RA (TA) and it served with Second Army in Normandy and North West Europe [REF].