Carl (Charles) Holzer was born and educated in villages about seventy miles from Vienna, Austria. After serving a five-year lithography apprenticeship with a printing firm in Vienna, he became a lithographic journeyman, travelling throughout Austria. He moved to London in 1902 where he found work at various commercial art studios and litho shops, particularly at Hübner Ltd, where his designs were used to advertise Pears, Lux and Sunlight soaps. He married Catherine Collatz in 1905 and they had three children. Despite thinking of himself as British, he had never undergone the naturalisation process, and therefore at the outbreak of World War One he was classed as an enemy alien.
Alexandra Palace was initially used as a transit centre for refugees fleeing from occupied Belgium. Once the last refugees had been processed in March 1915, the Palace was turned into an internment camp for enemy aliens, non-naturalised civilian men over the age of 16 from the countries with which Britain was at war. Along with 3,000 other men Holzer was interned at Alexandra Palace between 1915 and 1919, where he produced several portrait painting of his fellow internees. After the end of the war he returned to Hübner's Ltd, a design house in Tufnell Park. He became a British Citizen in 1926 and died in 1943 of heart failure.