Here is a look at the players in the e-mail chain, listed in alphabetical order by first name.
Aras Agalarov: Mr Agalarov is the president of Crocus Group, a Moscow-based real estate development company that licensed the Miss Universe pageant from the Trump Organisation in 2013 to host in the Russian capital. This is the point at which Mr Agalarov and his son, Emin Agalarov, became associated with the Trumps.
Mr Agalarov is mentioned in an e-mail from Mr Rob Goldstone as having met the "Crown prosecutor of Russia" who offered to provide incriminating information about Mrs Hillary Clinton.
Donald Trump: He is mentioned in the e-mail chain when Mr Goldstone suggested he wanted to discuss the matter with Mr Donald Trump Jr. The elder Trump was the Republican presidential candidate at the time.
Donald Trump Jr: The President's son coordinated the meeting with Mr Goldstone, Mr Paul Manafort and Mr Jared Kushner.
Emin Agalarov: The son of Mr Aras Agalarov is a vice-president of the Crocus Group and a pop music star in Russia. When Mr Goldstone first offered access to the information he had at his disposal, Mr Trump Jr requested a phone call with Emin.
Mr Goldstone mentioned that Emin could not talk because he was on stage in Moscow. It is not clear whether the two talked, but the next day, Mr Goldstone set up a meeting at Emin's request.
Hillary Clinton: She was the front-runner for the Democratic presidential nomination at the time.
Jared Kushner: Mr Trump Jr's brother-in-law. According to an NBC interview with Ms Natalia Veselnitskaya on Tuesday, he left the meeting after about 10 minutes.
Natalia Veselnitskaya: A lawyer with reported links to the Kremlin. It is not clear whether she was the "Russian government attorney" who Mr Goldstone suggested would participate in the meeting, but she was the person who attended. (In that NBC interview, she denied having ties to the government.) Mr Goldstone's e-mails suggest that the attorney - presumably Ms Veselnitskaya - flew in from Moscow for the meeting and was scheduled to be in court the same afternoon as the meeting.
Paul Manafort: The Trump campaign chairman attended the June 9 meeting. According to the NBC interview with Ms Veselnitskaya, he spent the entire meeting looking at his phone.
Rhona Graff: Mr Trump's long-time assistant.
Rob Goldstone: A British-born promoter who represents Mr Emin Agalarov. Along with the Agalarovs, he was involved in the 2013 Miss Universe pageant planning, which is how he came into contact with the Trumps.
Yuri Yakovlevich Chaika: There is no "Crown prosecutor" in Russia because it is not a monarchy. The New York Times reported that the reference was to Mr Chaika, Russia's prosecutor-general.