WASHINGTON (AP) — The first criminal charges to come from special counsel Robert Mueller's probe into foreign meddling in the 2016 election stem from different activities. A primer on those charged:

PAUL MANAFORT

Before Manafort became GOP presidential candidate Donald Trump's top strategist between late March and August 2016, he had a storied career in Republican politics.

A lawyer by training, Manafort gained prominence rounding up delegates for Gerald Ford at the 1976 Republican convention and helping manage Ronald Reagan's convention efforts in 1980. He founded a lobbying shop, known as Black, Manafort, Stone and Kelly, earning a reputation for both his flashy lifestyle and his willingness to take on less-than-savory clients, such as Democratic Republic of Congo's dictator, Mobutu Sese Seko.

In 1995, Manafort set up a new lobbying firm with Rick Davis, who later helped Manafort establish his political contacts in former Soviet states, including Russian oligarch Oleg Deripaska and Ukrainian oligarch Rinat Ahkmetov. Manafort's work in Eastern Europe came at a lucky time, as struggled in his domestic lobbying business and his spending on an ill-fated career as a movie producer left him nearly broke in the early 2000s.

As an adviser to Ukraine's pro-Russian Party of Regions, Manafort helped the party turn around its reputation as corrupt and under Russian influence, getting Ukraine's president elected in 2006. Manafort remained an adviser to the Party of Regions until 2014, when it was ousted amid popular protests.

Among Manafort's long-term friends was Thomas Barrack, who was also personally close with Trump. That connection and Manafort's perceived skill in Republican Party politics got Manafort his entree into Trump's campaign. In August 2016, he was ousted amid revelations of large payments listed in an alleged "black book" of under-the-table payments by the ousted Ukrainian government.

RICK GATES

Rick Gates was Manafort's deputy, both in the Trump campaign and in Manafort's work in Ukraine. Now 45, Gates began as an intern at lobbying firm Black, Manafort, Stone and Kelly, before furthering his career elsewhere.

But after working with another Republican lobbyist, Rick Davis, Gates came back into Manafort's fold. By the time that Davis took a leave from his partnership with Manafort to run John McCain's presidential campaign, Gates joined Manafort's new firm, Davis Manafort Inc and was working with Manafort to drum up business in former Soviet States. They hit gold in work performed for the Party of Regions, a pro-Russian Ukrainian political party, though that work fizzled out in 2014 after Ukraine's president fled to Russia amid popular protests.

Gates joined Manafort for the Trump campaign, too, serving as a top decisionmaker for day-to-day matters. But he never drew a Trump campaign paycheck.

When Manafort got booted from the campaign amid revelations about his Ukrainian political work and questions about how he'd been paid for it, Gates stayed on in Trump Tower as a Republican National Committee liaison to the campaign.

Gates work wasn't done after Election Day, however. He was tapped by Trump Inauguration Chairman Thomas Barrack, a friend of both Manafort's and Trump's, to manage the work of the inaugural committee. And he also took a post with a newly created political nonprofit to support Trump, America First Policies, though he stepped down amid controversy surrounding his and Manafort's work with a Russian oligarch, Oleg Deripaska.

GEORGE PAPADOPOULOS

Before joining Trump's campaign, Papadopoulos billed himself as international energy consultant — though he only graduated from DePaul University in 2009 and was largely unknown in foreign policy circles.

Trump's campaign named him as one of eight foreign policy advisers in March 2016, however, as it scrambled to develop policy positions on key international issues. The Washington Post previously reported he had tried to facilitate contact between Russian government entities and the Trump campaign.