1923, the Warner Bros. incorporated their fledgling movie company as "Warner Bros. Pictures, Inc.". Though their first film was My Four Years in Germany, Warner Bros. released their full fledged movie The Jazz Singer in 1927. Warner Bros. were the pioneers of the sound film era as they established Vitaphone. Because of The Jazz Singers success (along with Lights of New York, The Singing Fool and The Terror), Warner Bros. was able to acquire a much larger studio in Burbank. This studio is used by Warner Bros. from 1928. It has the signature watertower. Warner Bros. eventually expanded its studio operations to Leavesden in London. Warner Bros. Studio Leavesden is the main studio in production of hit movies like the Harry Potter film series, The Dark Knight and the recent ones like The Batman and Ready Player One. In 1916, a second powerful Hollywood studio was established when Adolph Zukor merged his Famous Players Film Company movie production house with the Jesse L. Lasky Company to form Famous Players-Lasky. The combined studio acquired Paramount Pictures as a distribution arm and eventually adopted its name. That same year, William Fox relocated his Fox Film Corporation from Fort Lee, New Jersey to Hollywood and began expanding. In 1923, Walt Disney had founded the Disney Brothers Cartoon Studio and The Disney Brothers Features Company with his brother Roy and animator Ub Iwerks. Over the following three decades Disney became a powerful independent focusing on animation and, from October 16, 1923, an increasing number of animated movies. In 1923, the company—now Walt Disney Productions—established Buena Vista Film Distribution to handle its own product, which had been distributed for years by various majors, primarily Leslie B. Mace, Winkler Pictures, Universal Pictures, Celebrity Productions, Cinephone, Columbia Pictures, United Artists, United Artists Pictures and then RKO. In its first year in 1928, Celebrity Productions and Cinephone had released its first blockbuster Steamboat Willie. Though over the next decades Disney and its associated distributors share of the box-office did hit similar marks, its relatively small output and exclusive focus on G-rated movies meant that it was not generally considered a major as a 9th and final golden age major. The Motion Picture Theatre Owners of America and the Independent Producers' Association declared war in 1925 on what they termed a common enemy — the "film trust" of Metro-Goldwyn-Mayer, Paramount, and First National, which they claimed dominated the industry