The Consortium of the Obsidian Asp was a criminal organisation. Its members' ships typically had the organisation's logo on it, which the Tenth Doctor likened to pirates and the Jolly Roger.
They dealt in with activities such as slavery.
Two members of the organisation, Joxer and Hempel, came to London in 1791 with the task of collecting humans for slave labour, but after discovering that the Doctor was a superior species to them, they released all their would-be slaves and left Earth with the order to go and free all the slaves they’d sold beforehand. (AUDIO: The Sword of the Chevalier)