Edward Brian ["Ted"] Seago was born in March 1910 in Norwich. He had a limited education, and from 1923 was an apprentice to the artist Bertram Priestman. He subsequently toured England, Ireland, and France with a travelling circus and carried out espionage in Europe before World War Two. His experiences with the travelling circus are recorded in his "Circus Company" (1933), "Sons of Sawdust" (1934), and "Caravan" (1937). He contributed paintings with poems by his friend John Masefield, in the publications "The Country Scene" (1937), "Tribute to Ballet" (1938), and "A Generation Risen" (1942).

During World War Two Seago served as a camouflage officer in the Royal Engineers under his painting companions Field Marshal Sir Claude Auchinleck and Lieutenant-General Sir Harold Alexander. He was the author of "Peace in War" (1943) and "High Endeavour" (1944) and "With the Allied Armies in Italy" (1945).

After the War Seago travelled and exhibited across the world including Canada, South Africa and the USA. He was one of the artists officially invited to paint the coronation of Elizabeth II in 1952, and in 1956 accompanied the Duke of Edinburgh on his tour of Antarctica. He also painted a number of royal portraits including King George VI and Queen Elizabeth, Queen Elizabeth II, Prince Philip and Princess Margaret.

He was elected to the Royal Society of British Artists in 1946, made an Associate of the Royal Society of Painters in Water Colours in 1957 and a full member of the Society in 1959.

Seago died, unmarried, in January 1974.