Selwart's stage appearances, where some say he did his best work, on Broadway as well as around the country and in Canada included, besides "The Pursuit of Happiness," "Candle in the Wind" by Maxwell Anderson, with Helen Hayes, where he played his first German Nazi officer role, a type of character he came to specialize in, "The Laughing Woman," with Helen Menken, "Autumn Crocus,", "Seeds in the Wind," "Liliom," and "The Hidden River," in 1957, among many others. His last American stage appearance was in "Brecht on Brecht," on tour, in 1964. In addition, he also studied drama in New York, at the Actor's Studio and in California, with Michael Chekov. He was a member of Eva Le Gallienne's Civic Repertory Company, appearing in "Peter Pan," "Alice in Wonderland," and directed Wedekind's "Spring's Awakening," in which he also appeared, there as well, directing the fledgling actress who later became an important writer and poet, the Belgian-American May Sarton, in one of her earliest stage roles. Primarily a stage actor who acted in film, he performed most notably in Fritz Lang's "Hangmen Also Die!" in 1943, with a script by Bertolt Brecht and John Wexley, as a Nazi Gestapo chief, and in Joseph L. Mankiewicz's colorful 1954 feature, with Ava Gardner and Humphrey Bogart, "The Barefoot Contessa," as the Pretender King. He also made a brief speaking part appearance in Luchino Visconti's Italian "Senso," also in 1954, at the beginning of the film in the opera house scene, as an Austrian officer. Other familiar titles are: "Anzio" by Edward Dmytryk; "The North Star," directed by Lewis Milestone with a script by playwright Lillian Hellman, with Erich von Stroheim; "Edge of Darkness," also by Milestone, his first film role, in 1943 where he played his first film German soldier role, opposite Judith Anderson; "Wilson" where he played the German diplomat, Count von Bernstorff; "The Cross of Lorraine," with Gene Kelly; "The Hitler Gang," playing the Nazi official Alfred Rosenberg and "Romanoff and Juliet," starring and from the play by Peter Ustinov, and an Italian-American adaptation of Homer's Iliad, "Helen of Troy," Directed by Robert Wise, with Rossanna Podesta, Jacques Sernas, and,in two featured roles, Tonio Selwart playing opposite a then almost unknown Brigitte Bardot, in 1956.
Always appearing as a support performer in English-language films, Selwart was to be seen as a lead in Italian and French films, notably in "Lupo della Frontiere" ("Wolf of the Frontier") during the 1950s. He spoke fluent Italian, English and French which helped him with roles in several countries. Starting from the late 1940's till the 1950s and 1960s, he also appeared on American television, making guest appearances in drama programs.
Fittingly enough, Selwart was himself an officer and fought in World War I on the Austro-Hungarian side, as a Lieutenant in the Cavalry.
He derived his nickname "Tonio" from his first name and from his family background (his parents were Austrian, a grandmother Italian) and was familiar with the short story "Tonio Kroger," by a friend of his, Thomas Mann, having a taped recording of the story being read by Mann himself, which dealt with a young artist in pre-WWI Germany, half-German, half-Italian.
Selwart was very popular and had many friends in the film and theater world. His wife, Claire Volkhart, a painter and sculptor, died in Germany in 1935 and his longtime companion, Ilsa, a Paris-born Spanish artist, died in 1968.
He died at the venerable age of 106 in New York City.
Most of the information given here comes from Gretchen Berg, a journalist who interviewed Selwart in his home in 1992, in New York. She kept in touch with him until 1999, three years before his death. She had actually met him almost thirty years earlier, in 1963, when she was 20 and he was 67 at the Hotel St. Moritz with her father, film critic and historian Herman G. Weinberg and their mutual friend, Fritz Lang. Out of this encounter she fashioned a two-part article, "La Nuit Viennoise," published in Cahiers du Cinema, Paris, in which she wrote about that evening, mentioning Selwart as having been a part of the festivities. She photographed Mr. Selwart in 1998 and 1999 as well, in his apartment in New York.