Before Paul Manafort ran President Donald Trump s campaign, he spent years working with Russians and Ukrainians with ties to the Kremlin, cashing out millions of dollars in the process.

He is now on trial for bank fraud and tax evasion charges in Virginia while he awaits another in D.C. This trial is one of the most closely watched events to date to come out of special counsel Robert Muellers investigation into the Trump campaigns possible collusion with Russia.

Here are some of the key witnesses who will appear at trial, as well as the Ukrainians and Russians well be hearing about.