Robert Downey Jr paid tribute to his father, Robert Downey Sr, who has died aged 85. He had Parkinson’s disease for more than five years. "Dad passed peacefully in his sleep after years of enduring the ravages of Parkinson's," the <i>Iron Man </i>star wrote. "He was a true maverick filmmaker, and remained remarkably optimistic throughout." Downey Sr was a filmmaker and actor, best known for writing and directing 1969’s <i>Putney Swope</i>. The film starred Arnold Johnson as the only black man on an advertising film’s executive board after he is accidentally put in charge. The film was hailed a success for its satirical view on race in America as well as corporate culture. He also acted in films, playing Thomas Bateman in <i>To Live and Die in LA</i>, the studio manager in <i>Boogie Nights</i> and the show director in <i>Magnolia</i>. Born in New York City in 1936 as Robert Elias Jr, he later changed his surname to Downey – his stepfather's name – in order to enlist in the army early. After the army, he got into filmmaking by chance while living in New York with his sister. The last film he directed was the 2005 documentary <i>Rittenhouse Square</i>, about a small Philadelphia park. The elder Downey is also survived by his wife, bestselling author Rosemary Rogers. <i>- With additional reporting from the Associated Press</i> <br/>