The investigation, which cost more than $16.6m in its first 11 months, can be broken down into four distinct parts which have all led to indictments:
Manafort and his business connections to Russia following years of work in support of the former Ukrainian president Viktor Yanukovych.
Russian use of fake social media accounts to influence the 2016 election.
Russian hacking of the Democratic party and the Clinton aide John Podesta – and the subsequent leak of thousands of emails by WikiLeaks.
Trump campaign connections to Russia – including the Trump Tower meeting and the adviser George Papadopoulos’s involvement with a professor who told him the Russians had “dirt” on Clinton including “thousands of emails”.