Humphrey Bogart was born into a wealthy and famous family on December 25, 1899, in New York City. His father was a heart surgeon and his mother, Maud Humphrey, was a well-known illustrator who used her son as the model for the Mellin's baby food company. Humphrey Bogart later said that there was a point in the early 1900s when "you couldn't pick up a [...] magazine without seeing my kisser on it." At 17, Bogart joined the Navy during World War I, and it was during this time that he was hit in the face by a prisoner wearing handcuffs. Bogart was left with a scar on his upper lip that gave him his now famous way of speaking.

After the war, he went into the theater, first as a stage manager and then as an actor. He appeared in a few films at Fox in the early 1930s, but it wasn't until he returned to Broadway in 1934 that he became a star. The play was The Petrified Forest and Warner Bros. bought the film rights. Star Leslie Howard insisted that Bogart be brought to Hollywood to repeat his stage role as the killer, Duke Mantee. Bogart was a sensation and Warner Bros. signed him to a long-term contract. However, Bogart played mainly supporting roles and gangsters until The Maltese Falcon made him a genuine movie star, which he remained until his death from esophageal cancer in 1957.

Mary Astor was born Lucile Langhanke on May 3, 1906, in Quincy, Illinois. She began her career as a model, and appeared in her first film at the age of 14. Her parents were determined that she would be a star, and she quickly made her mark in silent pictures. Astor's career was threatened in the mid-1930s when her diary was stolen during her divorce trial, revealing her love affairs. Warner Bros. stood by her and she was able to resume her career. As she got older, Astor began to play mother parts, most notably in Meet Me in St. Louis (1944) and Little Women (1947). Tired of playing mothers, she left Hollywood and later became a best-selling novelist. Mary Astor died in 1987 of a heart attack at the age of 81.

Sydney Greenstreet was born on December 27, 1879 in Sandwich, England. He worked as a tea planter and brewery manager before becoming an actor, making his stage debut in Sherlock Holmes in 1902. Greenstreet worked in the theater in London, eventually touring in the United States and appearing on Broadway. It was while appearing in Robert Sherwood's There Shall Be No Night that he was discovered by director John Huston and brought to Hollywood, where he made his film debut at the age of 62 in The Maltese Falcon. Greenstreet quickly became one of the top character actors in Hollywood. The Maltese Falcon was also the first time that he worked with Peter Lorre - they would go on to make nine other films together, including Casablanca (1942) and The Mask of Dimitrios (1944). Sydney Greenstreet died of a heart attack in 1954 at the age of 74.

Peter Lorre was born Laszlo Lowenstein in Rozsahegy, Hungary on June 26, 1904. His first acting appearance was playing one of the Seven Dwarves in a school production of Snow White . Although he was only 5'3", he wanted to be an actor, but his father didn't approve. To make his father happy, Lorre got a business degree and worked as a bank teller, but managed to get himself fired so he learned acting instead. After several lean years, he changed his name to Peter Lorre and began to find work on the stage in Switzerland and Germany. His creepy performance in Fritz Lang's 1931 film classic, M (1931), brought him international stardom. Because Lorre was a Jew, he had to flee Germany in 1933 when Hitler rose to power. He and his wife settled in England, where he worked with Alfred Hitchcock in The Man Who Knew Too Much (1934). That film earned him a contract at Columbia Studios where he appeared in Mad Love (1935), cementing his reputation as one of the best and most unusual character actors in film history. Peter Lorre died of a stroke on March 23, 1964 at the age of 59.