[1] He was educated at the Aldro prep school, Eastbourne, the Lyceum Alpinum Zuoz in Switzerland, and at Jesus College, Cambridge,[2] but left without a degree.

[citation needed] During the Second World War, Hallowes initially served with the 2nd Battalion, the Gordon Highlanders in the defence of Malaya against Japan in 1942.

They took a boat to the east coast of Sumatra, and walked to Padang, from whence they were rescued by Royal Navy destroyer which called in to refuel after the Battle of the Java Sea.

Hallowes led his team, code-named "Jeremy", with French Lieutenant Henri Charles Giese and radio operator Sergeant Roger Leney.

[citation needed] He and his team travelled via Algiers to arrive in the south of France on 24 August 1944, where they were met by American SOE operative Virginia Hall.