Leon Greenman was born in London in 1910. His paternal grandparents were Dutch, and at an early age, after the death of his mother, his family moved to Holland, where Leon eventually settled with his wife, Esther, in Rotterdam. Leon was an antiquarian bookseller, and as such travelled to and from London on a regular basis. In 1938, during one such trip, he noticed people digging trenches in the streets and queuing up for gas masks. He hurried back to Holland with the intention of collecting his wife and return with her to England. The whispers of war were growing louder and louder.