Who is Paul Manafort, the former Trump campaign chairman found guilty? Manafort was found guilty on eight counts of financial and tax-related crimes.

President Donald Trump has repeatedly called his former campaign chairman Paul Manafort "a nice man."

Now he can also be called a guilty one.

Manafort was found guilty on eight counts of financial crimes as part of the first major prosecution won by the team led by special counsel Robert Mueller's team that's investigating Russian meddling in the 2016 election.

The crimes he was found guilty of stem from his work in the U.S. and abroad mostly in the years before his involvement with the 2016 election and are unrelated to his campaign work, but the charges stemmed from findings from Mueller's investigation.

Political work in Ukraine

Manafort, 69, worked as a political consultant for Ukraine's since-toppled President Viktor Yanukovych, and his political party, the Party of Regions, starting in 2006 and continuing till at least 2010, according to a senior party official who worked with Manafort.

The party official, who spoke to ABC News on condition of anonymity because of the sensitivity of the topic, said Manafort had acted as Yanukovych's "personal trainer" in political campaigning and credited the American political consultant with Yanukovych's winning Ukraine's presidency in 2010.

That had been a remarkable comeback for the Ukrainian politician whose attempt to win the presidency six years earlier was marked by allegations of election fraud, helping to spark the country's peaceful Orange Revolution. The party official said Manafort was particularly valued as a strategist and also for his expertise in modern polling techniques.

The Associated Press reported that Manafort's firm had lobbied in the U.S. on behalf of the Ukrainian political party even though he did not disclose his work as a foreign agent, as mandated by federal law.

Manafort later did register as a foreign agent, on June 27, 2017, for his past work on behalf of the Ukrainian party.

In July, the FBI executed a search warrant at Manafort’s Virginia home, stemming from the Russia investigation. A source familiar with the matter described armed FBI agents’ waking Manafort early in the morning as they knocked on his bedroom door.

Republican political involvement in the US

In the United States, Manafort was known in Republican Party politics for decades before joining the Trump campaign in March 2016 as the campaign’s convention manager and then getting promoted to campaign chairman two months later.

He told CNN in April 2016 that he has known Trump "since the 1980s."

Unlike much of Trump's relatively young staff that helped the real estate mogul earn his early primary victories, Manafort was arguably more of an establishment figure when he was brought on.

The Trump campaign credited him with experience spanning three decades, but one of his biggest victories came four decades ago.

Manafort reportedly played a significant role in the 1976 convention where Gerald Ford ended up winning the nomination in spite of a fight from Ronald Reagan and Bob Dole. That’s the last time Republicans had no clear nominee going into the convention.

Manafort went on to work for Reagan and George H.W. Bush in later years.

When asked whether he considers himself an establishment insider, Manafort was not ready to commit one way or another.

"Depends on who you talk to if I'm part of the establishment or part of the anti-establishment," he told CNN in April 2016. "But the point is that I understand the establishment. I've run campaigns. That doesn't make you the establishment.

"Do I have relationships that go back into the system? Yes. Some of those relationships see me as a bridge to Trump now. They want to be for Trump. They didn't have a way in. They're now talking to me, finding a way in," he said.

Manafort left the Trump campaign in August following the New York Times article on the Ukrainian ledger entries.

Legal troubles

Manafort surrendered to the FBI in October 2017 in the face of a federal indictment that stemmed from alleged financial and tax-related crimes.

That led to the recent trial of Manafort, who was indicted on 18 counts. The trial included testimony from his former longtime business associate Rick Gates, who pleaded guilty in February to charges of conspiracy and lying to federal authorities. Gates initially was charged alongside Manafort but he then cooperated with the special counsel and has yet to be sentenced. Gates' testimony included information on more than a dozen offshore accounts that he and Manafort failed to report to the government.

The federal judge presiding over Manafort's case declared a mistrial on the other 10 counts that he faced because jurors could not reach a consensus. He was found guilty on the remaining eight.

Manafort now could end up spending the rest of his life in prison. His sentence has yet to be issued, but the eight guilty counts combined could lead to a maximum of 80 years in prison.

Beyond the trial that just finished, Manafort faces another trial next month that also stemmed from the special counsel's investigation. The charges he faces in that trial include obstruction of justice, conspiracy and foreign lobbying violations.

Editor's Note: This report has been updated from a version that ran in October 2017.