(CNN)Two-time Super Bowl champion Ben Roethlisberger has retired from the NFL after an 18-year career with the Pittsburgh Steelers.
Roethlisberger made the announcement on his Twitter page, saying: "The time has come to clean out my locker, hang up my cleats, and continue to be all I can be to my wife and children. I retire from football a truly grateful man."
Roethlisberger was drafted with the 11th overall pick by the Steelers in 2004, winning the Offensive Rookie of the Year award in his first season in the league.
During his time in Pittsburgh, he won two Super Bowl rings in the 2005 and 2008 seasons and was voted to the Pro Bowl on six occasions.
Known for his grittiness and determination, Roethlisberger quickly became a pillar for the Steelers in what has been a hugely successful run under head coaches Bill Cowher and later Mike Tomlin.
In his rookie season, he was the backup to Tommy Maddox for the season opener, but started Week 2. From there, he lead the team to a 13-0 record on the way to the AFC Championship game, which they lost to Tom Brady and the New England Patriots.
"He was in a very difficult position, having to be a rookie signal caller on a veteran offense where he wasn't asked to be the leader on the offense," Jerome Bettis, Hall of Fame running back and former teammate of Roethlisberger, said.
"It was a difficult transition for him because you're asking him to be a leader on the field, but when he stepped off the field, he was a rookie again. He handled it so well. We were able to keep winning, and we leaned on him.
"By the end of the year, he was a veteran guy because he had been through so much. On the field was just magical, the things that he was able to do and the way he played like a veteran in his rookie year. He had a challenge, but he was able to face it head on and did a great job."
In total, the Steelers earned 12 playoff berths under Roethlisberger's stewardship. The team also won eight AFC North Championships, appeared in five AFC Championship games and went to three Super Bowls.
He became the youngest quarterback to ever win a Super Bowl -- at age 23 -- when the team won Super Bowl XL and the second-youngest quarterback to ever win a second Super Bowl when the Steelers won Super Bowl XLIII.
The 39-year-old retires near the top of most quarterback statistical measures in what is likely a Hall of Fame career.
He is fifth in NFL history in pass completions (5,440) and fifth in total passing yards (64,088) -- only behind Brady, Drew Brees, Peyton Manning and Brett Favre.
"I don't know how to put into words what the game of football has meant to me and what a blessing it has been. I know with confidence I have given my all to the game and I am overwhelmed with gratitude for all it has given me."
Roethlisberger added: "The journey has been exhilarating, defined by relationships and fueled by a spirit of competition ... Football has been a gift, and I thank God for allowing me to play it. Surrounding me with great people, and protecting me through to the end with love and honor."