Joe Greene was drafted by the Steelers in 1969 with the No. 4 pick and played all 13 years of his career in Pittsburgh. The defensive tackle was named the NFL’s Rookie of the Year, as well as the Defensive Player of the Year in 1972 and 1974. He was selected to 10 Pro Bowls during his career. The Hall of Fame "cornerstone of the Steel Curtain" in the 1970s who helped lead the Steelers to four Super Bowl victories, Greene turned 69 years old on Sept. 24, 2015. We present these classic SI photos in honor of "Mean Joe."