MK Dons have signed former Derby captain and Republic of Ireland defender Richard Keogh.
The 33-year-old has not played since September 2019, when he sustained a serious knee injury in a car crash involving two of his Derby team-mates.
Tom Lawrence and Mason Bennett pleaded guilty to drink-driving.
Keogh, who was a passenger in one of the vehicles, was sacked by the Championship club for "gross misconduct" for his involvement.
MK Dons have not disclosed the length of contract that centre-back Keogh has signed with the League One club.
"I can't wait to get on the shirt and I'm looking forward now. I've missed a lot of football and you're getting someone who is going to be excited and hungry to play and push this team forward," Keogh told the club website.
He has won 26 caps for the Republic of Ireland and played at Euro 2016, starting group matches against Italy and France.
Keogh joined Derby in the summer of 2012 and played more than 350 games for the Rams.
He has played more than 500 games in a career that has also seen him have permanent spells at Coventry and Carlisle.
"Once I knew he was available, I was desperate to bring him in," said Dons boss Russell Martin. "I know how much he'll bring on and off the pitch.
"He probably turned down more lucrative offers to play here and, for me, it's a massive signing and it's a statement from him to say he wants to be part of it. He's been my number one target in that position for a long time - so I'm delighted to have it over the line."
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