Henri Leonard Thomas Peulevé was born to British parents on 29 January 1916, at Hastings on the Sussex coast. He and his older sister Annette spent their early years almost constantly on the move: in addition to several spells in England, they also lived in Algiers and at Dinard on the Brittany coast. Invited by a family friend to spend his summers on the Cote d'Azur, Harry soon developed a love for his adopted country and became a fluent French speaker.
Qualifying as an electrical engineer, Harry worked for Pye before moving to Baird's television company based at Crystal Palace. In 1936 he joined the BBC's new TV studios at Alexandra Palace, where he established himself as one of their first cameramen before the outbreak of war.