The thieves guild of Procampur has no known name or designation. Not many outside of the guild can confirm that it exists as if it was confirm-able the guards would not stop until the was smashed. We’ll call them The Unknown.
The Unknown is run by The Raven, a legendary spook who’s stories of amazing heists have been told for over a decade. Nearly any time a difficult heist is performed with no one caught or taking responsibility of the job, The Raven ends up getting credit. It’s possible that The Raven doesn’t exist and the leader has only taken the name to add to his credibility.
Regardless of his name or title the Guildmaster of the thieves guild runs a very disciplined crew and very rarely does any person in the guild know the names or faces of many other members; only enough to support their expertise. This secrecy is the only way the guild has been able to stay safe from raids or getting sold out by those who are caught.