Born Gunther Edward Arnold Schneider in New York City to German immigrant parents; he went to school at the East Side Settlement House. His interest in acting came at an early age and he made his stage debut at the age of 12 in The Merchant Of Venice, playing the role of Lorenzo. He made his professional stage debut in 1907. After this, he found work as an extra with Essanay Studios after it's move from Chicago westward. Many of these roles do not show up in his list of credits. He first credited role, and on IMDb it looks like his first film role, came in 1916 with The Misleading Lady. By 1917 he was getting lead roles in silent films. His last credited role in a silent film came in 1920 with The Cost. The last silent film in which appeared was simply as an extra in the huge cast of Victor Sjöström's He Who Gets Slapped (1924), starring Lon Chaney Sr. Arnold then left the motion picture industry for the stage; he would not return until well into the talking era. He made his film return in 1932 in the short Murder in the Pullman and from then on had steady work, becoming one of Hollywood's most recognizable character actors. His specialties became characters that were either authoritarian figures or rogues. In the 1947 he became the star of his own radio show Mr. President, which ran through 1953. He also got into television work in the 1950's. In addition to his acting career, he served as president of the Screen Actors Guild from 1940 through 1942; and he was co-founder of I Am An American Foundation. He worked right up until the time of death at the age of 66; in all he would appear in more than 150 films. His last time in front a camera came as the host of the television program Strange Stories the year of his death. He passed away suddenly from a cerebral hemorrhage on the 23rd of April 1956 in Encino, California. He is buried in the catholic San Fernando Mission Cemetery in the Mission Hills part of Los Angeles. He grave marker somewhat comically states, "He's not dead--He's just away."