In which theatre of World War II did Popski's Private Army operate?

No. 1 Demolition Squadron, PPA, was a unit of British Special Forces set up in Cairo in October 1942 to attack Rommel's fuel supplies. It was "special" not only in the usual military meaning of “special forces,” but also in its unorthodox organisation and methods.

The unit was headed by Major Vladimir Peniakoff (1897-1951), a Belgian Jew of Russian heritage. As an Arabic-speaking British army officer, Peniakoff had been involved in operations behind enemy lines in Libya. He acquired the nickname “Popski,” based on a cartoon character, because radio signallers had problems with the name "Peniakoff."

In 1942 the newly-named Popski was invited to set up the new unit, which still lacked a name. Lieutenant-Colonel John Hackett, co-ordinator of British raiding operations, grew exasperated at Peniakoff’s delay in sorting out an official name. In response to Hackett's "You had better find a name quick or we shall call you Popski's Private Army" Popski simply replied "I'll take it". PPA was officially born.

PPA was a flexible, mobile and effective force, using small groups of jeeps equipped with machine guns. It was also efficient, having a tiny headquarters. It played a major role in driving Axis forces out of Egypt and Libya and later served in Italy.

PPA was run informally: no saluting, no drill, few rank distinctions; everyone was expected to know what to do and to get on with it. There was only one punishment for failure: immediate return to one’s previous unit.