When he was ten years old, the younger Biddle was in an exhibition match with Bob Fitzsimmons, who knocked him into a wall with a punch traveling about two inches.

A party he held for the boxer at the hotel was marked by the loss of many bottles of fine champagne (at great expense due to prohibition in the United States).

[5][6] After Biddle was appointed Envoy Extraordinary and Minister Plenipotentiary to Norway on July 22, 1935, he settled the Irving case out of court to avoid a bond required before leaving the country to assume the post.

It was widely suspected he was a political appointee resulting from his support of the Democratic Party and George Howard Earle III, its 1934 successful candidate for Governor of Pennsylvania.

[10] After the escape, he joined the Polish government in exile in France until June 1940, when he and his wife Margaret received transit visas from the Portuguese consul Aristides de Sousa Mendes, in Bordeaux, and crossed into Portugal.

[9] During the period, he owned Saint Hill Manor in West Sussex, a country estate which was later sold to Church of Scientology founder L. Ron Hubbard.

In January 1944, Biddle resigned from the State Department and joined the Army as lieutenant colonel to serve on the staff of Dwight Eisenhower.

His contacts with "underground" movements and free military units in occupied nations provided intelligence for the planning of Operation Overlord, the Allied invasion of France.

[20] Through this marriage he had two stepchildren, (Margaret) Boyce Schulze and Theodore Schulze Jr, as well as a son before their divorce in 1945:[20] He married as his third wife, in 1946, Margaret Atkinson Loughborough (1915–2013), the former wife of William Ellery Loughborough[22] and had two more children: He died November 13, 1961, in Washington, D.C., at the Walter Reed Army Hospital.

[26] The one published picture of Biddle without his impeccable suit was when he had to pack in a hurry to escape German bombers in Poland via Romania.

[28] His sister Cordelia Drexel Biddle wrote a book with Kyle Crichton about the family, focusing on her marriage with Angier Buchanan Duke who was the brother of Anthony's first wife.