Tom Brady announced his departure from the New England Patriots on Tuesday, ending a glittering 20-year run with the franchise which saw him become the most successful quarterback in NFL history.

Brady, 42, confirmed his departure in a series of posts on social media but did not divulge where he will play next season.

"Although my football journey will take place elsewhere, I appreciate everything that we have achieved and am grateful for our incredible TEAM accomplishments," Brady said in a statement.

"I don't know what my football future holds but it is time for me to open a new stage for my life and career," he added.

Brady is widely regarded as the greatest quarterback in NFL history, winning a record six Super Bowl titles in a career with the Patriots spanning three decades.

He has won a record four Super Bowl MVP awards and has been the NFL's season MVP three times -- in 2007, 2010 and 2017.

He is also the oldest quarterback to win a Super Bowl, guiding the Patriots to victory over the Los Angeles Rams last year at the age of 41.

Brady's nine total Super Bowl appearances are also a record for any NFL player, a testament to his remarkable longevity.

Quarterback Tom Brady is leaving the New England Patriots after 20 years with the NFL giants
Quarterback Tom Brady is leaving the New England Patriots after 20 years with the NFL giants GETTY IMAGES NORTH AMERICA / Maddie Meyer

His departure from New England ends one of the NFL's iconic double-acts, with Patriots head coach Bill Belichick.

Belichick has been in charge in New England from the start of Brady's career, plucking him from obscurity with the 199th pick of the 2000 NFL draft and moulding the youngster into a champion quarterback.

Belichick described Brady as the "greatest quarterback of all time" in a statement Tuesday.

"It has been a privilege to coach Tom Brady for 20 years," Belichick said.

"He didn't just perform. He didn't just win. He won championships over and over again.

"Sometimes in life, it takes some time to pass before truly appreciating something or someone but that has not been the case with Tom."

New England Patriots quarterback Tom Brady and head coach Bill Belichick celebrate after the team's comeback Super Bowl victory over Atlanta in 2017
New England Patriots quarterback Tom Brady and head coach Bill Belichick celebrate after the team's comeback Super Bowl victory over Atlanta in 2017 GETTY IMAGES NORTH AMERICA / Kevin C. Cox

Brady has repeatedly stated that he plans to play until his mid-40s but speculation about his future had raged after he failed to reach agreement with the Patriots about an extension last year.

Brady's relationship with Belichick has also reportedly come under strain in recent seasons, with the quarterback increasingly at odds with the coach's austere, tough-love management style.

Nevertheless, Brady had remained close to the Patriots' billionaire owner Robert Kraft, who said Tuesday that he viewed the quarterback like a son.

"How do I possibly sum up the depth of my gratitude to Tom Brady for what he's given us these past 20 years, or the sadness I feel knowing it's ending?" Kraft said in a statement. "I love Tom like a son and I always will.

"I had hoped this day would never come, but rather that Tom would end his remarkable career in a Patriots uniform after yet another Super Bowl championship.

"Unfortunately, the two sides were unable to reach an agreement to allow that dream to become a reality.

"While sad today, the overwhelming feeling I have is appreciation for his countless contributions to our team and community."

Brady was often visibly frustrated during what turned out to be his final season with the Patriots, often operating with an inexperienced receiving corps and sorely missing the giant presence of retired tight end Rob Gronkowski.

The Patriots were bundled out in the wildcard round of the playoffs in January, suffering an upset 20-13 defeat at home to the Tennessee Titans.

Since that playoff exit, Brady has been tightlipped about his future although a number of teams have reportedly been targeting him ahead of the start of free agency, which gets under way on Wednesday.

He had been linked with a possible move to Tennessee but that option was taken off the table when the Titans reportedly opted to retain Ryan Tannehill instead.

With the Titans out of the picture, three teams are seen as the likeliest options for Brady -- the Tampa Bay Buccaneers, the Los Angeles Chargers and the Las Vegas Raiders.

While a move to Tampa Bay would be seen as a marked step down -- they have not reached the playoffs since 2007 -- both the Raiders and Chargers might be attractive to Brady for different reasons.

The Raiders will start next season in their sparkling new stadium in Las Vegas while the Chargers, who split with veteran quarterback Philip Rivers at the end of last season, are also looking to make a marquee signing as they prepare to move into their new $4.9 billion (4.46 billion euro) SoFi Stadium home in Los Angeles.