In a dramatic reversal, former Trump campaign chairman Paul Manafort pleaded guilty Friday morning to federal criminal charges and agreed to cooperate with special counsel Robert Mueller’s Russia probe.

Manafort’s decision to cooperate with Mueller is a potentially grievous blow to President Donald J. Trump, who had supported Manafort loudly and publicly, even as he also tried to distance himself from his onetime campaign manager’s Ukraine work.

The recent revelation by Trump attorney Rudy Giuliani that Trump and Manafort had a joint defense agreement further suggested that the legal and political fate of the President was inextricably tied to Manafort, the once high-flying GOP operative who made millions representing the pro-Russia regime in Ukraine.

Manafort arrived in the courtroom a few minutes past 11 a.m. ET on Friday, dressed in a dark suit and pink tie. He appeared calm and expressionless for most of his time in the courtroom, as he typically did throughout his weekslong trial in Virginia. Present in the courtroom as usual were his wife, one of her close friends, and his spokesman, Jason Maloni.

Prosecutors in the DC case against Manafort filed a Superseding Criminal Information on Friday morning in the Washington D.C. case, charging Manafort with a single count of conspiracy against the United States and a single count of conspiracy to obstruct justice through witness tampering, both arising from his work in Ukraine.

As a potential witness to alleged collusion between the Trump campaign and Russia during the 2016 campaign, Manafort became an early and sustained focus of the Mueller probe. Manafort had insisted on his innocence and fought the criminal charges relentlessly, even after many of his assets were frozen by the government, the legal bills began piling up, and his top protege flipped and testified against him

The pressure on Manafort only grew after he was convicted last month in a Virginia trial on bank fraud and tax fraud charges brought by Mueller. Manafort’s plea agreement comes just days before a second jury trial was scheduled to start in D.C., where he was charged with money laundering, witness tampering and failure to disclose foreign lobbying. The criminal charges against Manafort did not directly pertain to Russia meddling in the 2016 election or to collusion with the Trump campaign.

The reported deal comes after a number of reports of their ongoing discussions in recent days. Manafort and Mueller had also been in plea talks while the jury was in deliberations during his Virginia trial, but those negotiations had fallen through.

The jury in the Virginia trial had found Manafort guilty on eight of the counts brought by Mueller, while dead-locking on 10 others. In the D.C. case, Manafort was facing a judge less sympathetic than the judge who presided over the Virginia trial, U.S. District Judge T.S. Ellis.

The deal is the culmination of a federal investigation that has kept Manafort’s name in the headlines for more than a year, from summer 2017, when the FBI raided his residence in Virginia, through last October, when the charges first dropped, and into February, when his former business deputy and co-defendant Rick Gates reached his own plea deal with Mueller.

Manafort joined the Trump campaign in late March of 2016, and ascended to chairman before leaving in August as revelations emerged about his previous consulting work in the Ukraine.

Most of the charges Mueller brought against him stemmed from that pre-2016 Ukraine work, however some of the bank fraud allegations in Virginia overlapped with Manafort’s time on the campaign and after.

The D.C. trial that was averted by the new plea deal stood to pull back the curtain on the world of covert lobbying on behalf of foreign powers in the nation’s capital. Top lobbyists of both parties were implicated in the case, as was a major law firm. Manafort was lobbying on behalf of a pro-Russian party in Ukraine, the Party of Regions, and was credited of resuscitating the career of its leader, Viktor Yanukovych, who won the presidency in 2010. Yanukovych was ousted from the country in 2014, and Manafort’s consulting work in Ukraine dried up, according to evidence presented by the prosecutors in the Virginia trial.

Manafort has been in jail since June, when the judge in the D.C. case, U.S. District Judge Amy Berman Jackson, threw him in pretrial detention for alleged witness tampering.