George Randolph Hearst Jr., board chairman of Hearst Corp and the oldest grandson of media mogul William Randolph Hearst, died today of complications from a stroke in Palo Alto. He was 84. Hearst was a director of the privately held media conglomerate for 50 years, according to the company. He succeeded his uncle, Randolph A. Hearst as board chairman in 1996. “As chairman of the board, he brought his vast experience and wisdom to bear during a time of incredible growth and helped guide us through periods of enormous change,” said Frank A. Bennack Jr., executive vice chairman and chief executive officer of Hearst Corp., in a statement. Hearst Corp. owns 15 daily newspapers, including the Houston Chronicle, San Antonio Express-News and San Francisco Chronicle. It also owns 20 magazines, including Esquire, Harper’s Bazaar and Cosmopolitan, 29 TV stations and shares in several cable networks.