Early life and education
King was born in 1809 and was educated in London and Paris. He became a doctor like his father, who practised in Dover, and began training at Guy's Hospital as a teenager in 1824. He was appointed curator of the Guy's Hospital museum, a position previously held by Thomas Hodgkin, in 1837, and three years later became a lecturer in comparative anatomy and comparative physiology. He also lectured in anatomical pathology and wrote prolifically in the Guy's Hospital Reports, particularly about cancer.