Thornton rejected his family's adherence to Liberal politics and became a supporter of the Conservative party. In 1880, he began his writing career with the pamphlet Recovered Thread of England's Foreign Policy, which espoused Conservative policies. Thornton followed this with the three-volume Foreign Secretaries of the Nineteenth Century (1891), Harrow School and its Surroundings' (1883), The Brunswick Ascension (1887) and The Stuart Dynasty (1890).[1]