H.A. Rey was born in Hamburg, Germany in 1898. As a child, he spent much of his free time in that city's famous Hagenbeck Zoo drawing animals, a precursor to his days of creating art, prints and posters. After serving in the army during World War I, he studied philology and natural science at the University of Hamburg.
H.A. Rey then married Margret Rey and they moved to Montmartre for four years. The manuscript for the first Curious George books was one of the few items the Reys carried with them on their bicycles when they escaped from Paris in 1940, determined to find a better place for Rey to work on his art, prints and posters.
Eventually, H.A. Rey and his wife made their way to the United States, and Curious George was published in 1941, an indicator of the success that Rey achieved with his art, prints and posters.