Edward Louis Spiers was born in Paris, 7 August 1886, the son of Charles McCarthy Spiers and Marguerite Melicent Hack. He was mainly brought up by his grandmother, Lucy Harriet Hack, at her villa in Menton; Voutenay, his cousins' château in Burgundy; and Donadea Castle, in County Kildare, Ireland. He was educated privately and at boarding school in Neuwied, Germany, 1901-2. He married (1st) Mary Borden ('MS') in 1918 (she died in 1968), with whom he had one son, and (2nd) Nancy Maurice in 1969.

He joined the Kildare Militia, 1903, and was gazetted into the 8th Hussars, 1906. A polo injury prevented him travelling with his regiment to India and he transferred instead into the 11th Hussars, 1911. At the outbreak of the First World War, he was working at the French War Office in Paris and with British agents in Belgium. He was posted as a liaison officer between General Lanrezac of the French Fifth Army and Field Marshal Sir John French, the British Commander-in-Chief, 1914-17. He won the Military Cross and was wounded four times in action. He became head of the British military mission to the French War Office in Paris, 1917-20. At the time of his marriage to Mary Borden, in 1918, he decided to Anglicize his name and changed the spelling to Spears.

At the end of the war, he suffered a nervous breakdown and left the Army, 1920. He pursued a business career in London and stood for Parliament, first as National Liberal MP for Loughborough, 1922-4, then as Conservative MP for Carlisle, 1931-45. He was Winston Churchill's personal representative to the French Prime Minister, Paul Reynaud, May-June 1940, and escaped with General de Gaulle after the fall of France, continuing to work as British representative to him in London and North Africa, 1940. He was head of the British mission to the Free French in the Middle East, 1941, and first British minister to Syria and Lebanon, 1942-4.

On returning to England, he resumed his business career, most notably as Chairman of Ashanti Goldfields, from 1945, and Chairman of the Institute of Directors, 1948-66. He also concentrated on writing, producing a number of volumes based on his wartime experiences.

He died on 27 January 1974.

He was awarded the CBE, 1919, CB, 1921, and a knighthood, 1942; and was created a baronet, 1953.

His publications include: "Liaison, 1914" (1930); "Prelude to Victory" (1939); "Assignment to Catastrophe" (1954); "Two Men Who Saved France" (1966); "The Picnic Basket" (1967); and "Fulfilment of a Mission" (1977).