He was born Balint Stephen Biro in Budapest and was educated in Budapest at the Cistercian school and the Jaschnick School of Art. Worried by the rise of Adolf Hitler, in 1939 Biro’s father arranged for him to go to the Central School of Art in London to study. He was on holiday with an English family in Cornwall in the weeks before term began when the outbreak of the Second World War was announced. His student status protected him from being interned as an enemy to national security and allowed him to enrol at the Central School, then in London but soon evacuated to the Midlands. Biro studied illustration and was particularly influenced by John Farleigh’s wood engravings. Graduating in 1942, Biro planned to join the armed forces but was limited to working as an ambulance driver or for the National Fire Service. He joined the latter and also began work in the design side of publishing, first as a studio manager at the Sylvan Press and latterly as art director at the publishers John Lehmann until it went out of business in 1953. Biro was offered the chance of other employment but took the opportunity to go freelance, building on his excellent contacts for commissions.
