[1] On 14 April 1956, Cadogan was commissioned in the Coldstream Guards, British Army in the rank of second lieutenant to undertake his national service.

He owned Bedfordshire-based high-end upholstered furniture manufacturer, Peter Guild Ltd, (now based in Long Eaton) for a period during the 1990s.

In the Sunday Times Rich List 2023 ranking of the wealthiest people in the United Kingdom, his family was placed 36th with an estimated fortune of £5.57 billion.

[11] His third marriage was to Dorothy Ann Shipsey (married 1994), formerly the matron at King Edward VII Hospital for Officers.

[12] His titles passed to his elder son, Edward, who was educated at St David's College, Llandudno and served with the RAF in the first Gulf war.