Pittsburgh Steelers chairman Dan Rooney, one of the NFL's most influential and popular executives, has died. He was 84. A Steelers spokesman confirmed that Rooney died Thursday April 13 2017. Rooney took over operation of the team in the 1960s from his father, Art, who founded the franchise. Under Rooney's direction, the Steelers won four championships in six years -- Super Bowls IX, X, XIII and XIV. He also played a large role in assembling the 1974 draft class, considered the greatest class in NFL history, in which the Steelers picked four future Hall of Famers -- Lynn Swann, Jack Lambert, John Stallworth and Mike Webster. Rooney was appointed U.S. ambassador to Ireland in 2009 by President Barack Obama and served until his resignation in 2012. Rooney was born July 20, 1932, in Pittsburgh, to Art Rooney Sr., who founded the Steelers the following year. Rooney began working for his father in 1955 after graduating from Duquesne University. He was named president of the Steelers in 1975 and held that position until 2003, when he took on the role of chairman and his son, Art Rooney II, took over the presidency.