Sir Edward Peirson Thesiger (1842–1928), KCB, Clerk Assistant to Parliament, and Georgina Mary, daughter of William Bruce Stopford Sackville, of Drayton House, Thrapston, Northamptonshire, of the family of the Earl of Courtown.

Thesiger attended Marlborough College and the Slade School of Art with aspirations of becoming a painter, but quickly switched to drama, making his professional debut in a production of Colonel Smith in 1909.

After the incident in a barn explosion, his hands had been damaged and on return home, despite the Ministry of Pensions declaring it "too effeminate an occupation for men", Thesiger developed small sewing kits for soldiers similarly injured to provide activity and pain relief.

As Honorary Secretary Cross-Stitch, Thesiger was convinced that needlework could improve injured men's morale and earn some money, as he also obtained commissions, including an altar frontal for private use in Buckingham Palace.

[10] Thesiger moved in several artistic, literary and theatrical circles, and is reported to have spent time with Queen Mary, both doing needlework and commenting on the sexuality of proposed honours nominees.

[6] At various times, he frequented the studio of John Singer Sargent, befriended Mrs. Patrick Campbell, visited and corresponded with Percy Grainger and worked closely with George Bernard Shaw, who wrote the role of the Dauphin in Saint Joan for him.

[12] The London Standard wrote, "The character of Bertram Tully...is one of the happiest seen on the stage for a decade past...Mr. Ernest Thesiger achieved a real triumph.

B. Priestley's Benighted as The Old Dark House (1932), starring Charles Laughton in his first American film, together with top-billed Boris Karloff, Melvyn Douglas, Gloria Stuart, Raymond Massey and Lillian Bond.

Partly inspired by Mary Shelley's friend John Polidori and largely based on the Renaissance physician and botanist Paracelsus, it became Thesiger's most famous role.

The remainder of Thesiger's career was centered on the theatrical stage, though he did appear in supporting roles in films, prominent among which is The Man in the White Suit (1951), starring Alec Guinness.

He plays "Sir John," the most powerful, the richest, and the oldest of the industrialists (jointly with the trade unions) trying to suppress Guinness's invention of a fabric that never wears out and never gets dirty.

Later films included The Horse's Mouth (1958) with Alec Guinness, Sons and Lovers (1960), and The Roman Spring of Mrs. Stone, with Vivien Leigh and Warren Beatty (1961).