World War I. It may have carried over to the Second World War, but recall that the 51st Highland Division had to embark for France in 1939/1940 without the kilt-- not a good garment for expected use of blister agents like mustard gas, etc.--and that 10,000 of the division were captured and made PoWs after the French surrender in June 1940. The Highland Division then had to be reformed later in the war, albeit serving in North Africa, Sicily, the Normandy Campaign, and the Northwest of Europe and Germany.
My Great Uncle was with the Gordon Highlanders and was captured at St. Valery.
One rifle between the six of them.
He spent five years in a German P.O.W. Camp.