[1] He served in the First World War, at the outset as an enlisted man in the French Army then as an officer in The Royal Canadian Dragoons, and ended the war as an officer in the British Army, serving in Palestine as a major[2] in the 39th Battalion, The Royal Fusiliers (part of the "Jewish Legion").

[6] His defeat by Harry Legge-Bourke in the 1945 general election was one of only a few gains by the Conservative Party that year, with his Liberal colleagues Archibald Sinclair and William Beveridge similarly losing to Tory opponents.

During the Second World War he was Parliamentary Secretary to the Ministry of Supply in the Coalition Government 1940-1945.

Rothschild continued to support his father's Zionist causes, and donated IL 6,000,000 towards the construction of the Knesset building in Jerusalem, which was completed in 1966.

[8] His widow Dorothy de Rothschild inherited the surrounding estate, and maintained a strong interest in the house and collections until she died in 1988.