According to his death certificate Davis died at age 82 at 2:45 a.m. on Oct. 8 from an abnormal hearth rhythm, congestive heart failure and a heart muscle disease.
Davis was hired as coach and general manager of the Raiders at the age of 33 and later became principal owner.
He was also commissioner of the American Football League (AFL) in 1966 and was viewed as a driving force in the merger with the NFL that created the modern competition.
"Al Davis's passion for football and his influence on the game were extraordinary," said NFL commissioner Roger Goodell in a statement.
"He defined the Raiders and contributed to pro football at every level. The respect he commanded was evident in the way people listened carefully every time he spoke.
"He is a true legend of the game whose impact and legacy will forever be part of the NFL," he said.
Davis also took the Raiders away from Oakland to Los Angeles from 1982 to 1994 before returning the franchise to its original home.
He was inducted into the Pro Football Hall of Fame in 1992.