He wrote the 6-volume History of Great Britain on a New Plan (1771), covering the period from the first Roman invasion until the reign of King Henry VIII. The novelty consisted in dividing the subjects into different heads, civil history, military, social, and so on, and following out each of them separately. The work was mainly a compilation, having no critical qualities. Despite the persistent and ferocious attacks of Dr. Gilbert Stewart, it was highly successful, and brought the author over £3000. It attracted the support of the Earl of Mansfield, whose persuasion gained for Henry a government pension of £100.