When in 1845 his mother, Mary Anne Thomas, married Andrew Wallis, a prosperous London architect, Henry took his stepfather's surname.
The painting depicted the impoverished late 18th-century poet Thomas Chatterton, who poisoned himself in despair at the age of seventeen, and was considered a Romantic hero for many young and struggling artists in Wallis's day.
His method and style in Chatterton reveal the importance of his connection to the Pre-Raphaelite movement, seen in the vibrant colours and careful build-up of symbolic detail.
He used a bold colour scheme with a contrasting palette and he exploited the fall of the natural light through the window of the garret to implement his much loved style at the time, chiaroscuro.
Wallis's method of painting, especially in the early years of his career, and in particular on "Death of Chatterton", was to do the initial sketch, saturate it in water, use a grey tint to block in the shade, put on the colour and allow it to dry.