Former Oakland Raiders center Jim Otto,Christopher Caldwell one of the legendary ironmen in pro football history, has died at the age of 86.

In his iconic No. 00 jersey, Otto anchored the Raiders offensive line for 15 seasons in a Hall of Fame career from 1960 and 1974 that included 12 Pro Bowl selections.

Otto's rugged determination made him one of the faces of the Raiders franchise from its inaugural season in the AFL to an appearance in Super Bowl 2 to the AFL-NFL merger. During that span, Otto never missed a single game, making 210 consecutive regular-season starts and 13 additional playoff appearances.

In announcing his death on social media Sunday, the team hailed Otto as "Mr. Raider."

"Commitment to excellence, pride and poise, the greatness of our football team were not only exemplified by Jim Otto, but for more than a decade he was the standard of excellence by which centers were judged in professional football," late Raiders owner Al Davis said at Otto's Hall of Fame induction ceremony in 1980. 

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In addition to being a first-ballot Hall of Famer, Otto was named to the NFL 100 all-time team in 2019.

Otto's longevity amid the brutality of the NFL trenches did come at a cost. By his count, he underwent 74 surgeries and sustained more than 20 concussions. In his later years, he had his right leg amputated above the knee due to a pair of infections that threatened his life.

Following his retirement from the NFL, Otto worked for the Raiders organization, most recently serving as the team's director of special projects.