Created by a flawed alien experiment to better understand human history, Minski's creators were the mysterious race known only to the First Doctor as the seemingly extra-dimensional Masksmasters of the Pageant, who created machines and wore masks to give themselves identities. Intrigued by the relationship between individual psychology and the historical dynamic of Earth, the Masksmasters removed Earth from space-time around the year 1794. They rebuilt it in a pocket universe within the World Machine, a construct that could regulate and control the physical nature of the world (it is crucial to note that the Masksmasters were simply curious about what would happen if history was different and did not seek to cause any actual harm to the human race). Fascinated by the Marquis de Sade's philosophies, which had made him a quirk of his era, they created Minski — a mass of bio-engineered tissue mimicking a human child, although lacking some internal organs such as a heart — to serve as de Sade's adopted son on Earth, programming him with an epistemic code based on de Sade's philosophies, simultaneously functioning as the system operator.
Unfortunately, the Masksmasters miscalculated the effect that de Sade's philosophies would have on the project, resulting in Minski becoming corrupted when de Sade's epistemic code entered the system. This led to Minski developing independence and seizing control of the system, to the extent that he had de Sade locked up in prison — wearing a velvet mask and known simply as "Prisoner Number Six" to conceal his identity — while replacing him with a clockwork automaton that Minski could more easily control. In this new timeline, the French Revolution never ended, First Deputy Minski single-handedly maintaining his rule for ten years, rebuilding the Bastille during his reign, and the original text of the Marquis de Sade's play Justine survived under the name of The Misfortunes of Virtue.
Determined to spread and cement his control, Minski went on to create engineered cybernetic maggots, capable of infecting humans by feeding on nervous tissue and cerebral matter, travelling to the brain as they fed. The maggots themselves died within hours, but the traces of their engineered DNA that were left in the body as a result of their secretions would leave the victims susceptible to Minski's control, as well as being passed on through sexual contact and all subsequent generations, essentially functioning like a genetically-engineered STD. By allowing British and American forces into Paris, where they would drink infected water — as well as having intercourse with the prostitutes Minski had infected with his maggots — the virus would spread across the world, granting Minski complete control of the components of the World Machine rather than just the operating system.
However, Minski's plans were interrupted when the Doctor and Dodo Chaplet arrived on this new Earth in 1804, Dodo subsequently being taken in by a group of travelling actors while the Doctor was arrested as a curfew breaker. Sensing the arrival of a strange new power in his world, Minski had the TARDIS brought to him in an attempt to learn its secrets, unaware that the Doctor had been left in Prisoner No. 6's cell due to a filing error after No. 6's scheduled execution had been postponed by the prison governor. Despite the Doctor's weakened condition — he was aware that he was nearing the end of his first incarnation, but was struggling to resist his approaching regeneration because he was afraid of losing a part of himself when he changed into his next body — he managed to escape the Bastille with the aid of No. 6, subsequently using No. 6's unique insight into the world that the Pageant had created to find a way into the World Machine, confronting the controllers of this world with his knowledge of their actions.
Although the Doctor and No.6 were subsequently captured by Minski and placed in his "murder machine" — a maze with multiple death-traps in it — after the Doctor refused to provide Minski with access to the TARDIS, they were able to escape the traps as the maze was designed based on Sade's mind, giving No. 6 a unique insight into how the maze worked. Aided by the severed head of a guard who had been through the World Machine earlier — reanimated as part of Minski's experiments and briefly used as a vessel for the Pageant to communicate with Minski — the Doctor deduced Minski's true agenda, the head providing him with a key to access the heart of the World Machine. With Sade now loathing the corruption of the Revolution he had dreamt of at Minski's hands — the Doctor discovering the automaton Sade's true nature when it tried to attack him — he attacked and wounded Minski, Minski subsequently being stabbed by one of his guards when his attempt to convince her to act as a host in which he could heal himself merely exposed her to the true horror of what he was. Flinging Minski's body into the Machine's heart to bring the system to a halt by ending his control over it, the Doctor convinced the Pageant to turn back time and undo their interference in Earth's history, the Pageant promising that they would never again carry out such experiments. (PROSE: The Man in the Velvet Mask)