In 1918 he became chief delegate for the Supply of Relief to Poland. In February 1919 he was appointed British Commissioner for the Baltic Provinces during the British intervention in that region and helped draw up the treaty that established Estonia, Latvia and Lithuania. He adjudicated on the line of the border between Estonia and Latvia, which included dividing the town of Valga from Valka. He was secretary to the last Lord-Lieutenant of Ireland, Lord FitzAlan and was then Imperial Secretary for Northern Ireland, 1922 to 1926.