Sir John became MP for Chippenham in 1892, and a Member of London County Council from 1898 to 1904. He also served in the Second Boer War as aide-de-camp to Commander in Chief Paul Methuen, 3rd Baron Methuen, winning a DSO in 1900. He then chaired the Islington Commission. Appointed Governor of New Zealand in 1910, he was raised to the peerage as Lord Islington. After two years he returned to become first Under-Secretary of State for the Colonies and then Under Secretary of State for India.