Deakin was born in New Ferry on the Wirral and attended Calday Grange Grammar School. He left school at sixteen, and travelled around Ireland and Spain. He returned to London in the early 1930s where he met and started dating Arthur Jeffress. They spent much of the 1930s together travelling between London, Paris and Venice. During this time Deakin started as a painter but switched to photography. While in Paris in 1939 fashion illustrator Christian Bérard introduced Deakin to Michel de Brunhoff, editor of French "Vogue". From 1940 until 1945, Deakin served in the British Army Film Unit as a photographer, where he photographed the Second Battle of El Alamein.