Former Baltimore Ravens owner Art Modell died Thursday, the team reported on its website.
Modell, 87, was an NFL owner for 43 years, during which his teams won two championships.
He died peacefully of natural causes at Baltimore's Johns Hopkins Hospital, the team said.
"'Poppy' was a special man who was loved by his sons, his daughter-in-law Michel, and his six grandchildren," Modell's son, David Modell, said in a statement released by the team. "Moreover, he was adored by the entire Baltimore community for his kindness and generosity. And, he loved Baltimore. He made an important and indelible contribution to the lives of his children, grandchildren and his entire community. We will miss him."
Modell made a large mark on the league as chairman of its television committee, which helped shape lucrative rights fees for game broadcasts. He led owners' negotiations on the first collective bargaining agreement with players in 1968, according to his team biography.
He was also league president from 1967 to 1969.
Modell purchased the Cleveland Browns in 1961 for $4 million. The Browns won the National Football League championship in 1964, two years before the NFL and the rival American Football League agreed to merge.
In 1996, he moved the team to Baltimore, where, playing as the Ravens, the team won the 2001 Super Bowl. He stepped aside as owner in 2003.
Maryland Gov. Martin O'Malley hailed Modell for his contributions to Baltimore and the state.
"He helped reinvigorate Baltimoreans' sense of pride in their team and their city," he said in a statement.
Modell is survived by two sons and six grandchildren. His wife, Pat Modell, died last year.