Hyacinth Robinson, ‘a little presumptuous adventurer, with his combination of intrinsic fineness and fortuitous adversity’ was conceived by James while he was walking the streets of London.

Even with his poor upbringing, Hyacinth developed aesthetic tastes that heighten his awareness of the misery that surrounds him. He is then drawn into the secret world of revolutionary politics, and make a vow to assassinate a major political figure. It was not long after that he met the beautiful Princess Casamassima, whose world of wealthe and nobility, art and beauty, made him lose the faith in radicalism.