Jack L. Warner Jack L. Warner Jack Leonard "J. L." Warner (August 2, 1892 – September 9, 1978), born Jacob Warner in London, Ontario, was a Jewish Canadian-American film executive who was the president and driving force behind the Warner Bros. Studios in Burbank, California. Warner's career spanned some 45 years, its duration surpassing that of any other of the seminal Hollywood studio moguls. As co-head of production at Warner Bros. Studios, he worked with his brother, Sam Warner, to procure the technology for the film industry's first talking picture. After Sam's death, Jack clashed with his surviving older brothers, Harry and Albert
Harry Warner their own film production company. They named their new company Warner Features. Once Warner Features was established, Harry acquired an office in New York with his brother Albert, sending Sam and Jack to run the new corporation's film exchange divisions in San Francisco and Los Angeles. In 1917, Harry won more capital for the studio when he was able to negotiate a deal with Ambassador James W. Gerard to make Gerard's book "My Four Years In Germany" into a film. In 1918, after the success of "My Four Years In Germany", the brothers were able to establish a studio near