Great Fire of London

The Great Fire of London was a massive fire started when a Terileptil weapon overloaded in a bakery on Pudding Lane, London on 2 September 1666. (PROSE: Doctor Who and the Visitation) The Fifth Doctor and his companions Adric, Nyssa and Tegan Jovanka left the scene while Richard Mace attempted to put the fire out. The fire proved helpful in clearing plague from the city. (TV: The Visitation) A later incarnation took credit for the fire, but stated it was completely necessary. (COMIC: Black Death White Life)

Prior to witnessing the cause, the Doctor had been accused of starting the fire. (TV: Pyramids of Mars) The Fourth Doctor witnessed the outset of the fire at a distance and urged the Republicans and the forces of Charles II to stop fighting and work together to put out the fire. Sergeant Mullens, suspicious of the strangeness of the Doctor and Sarah Jane Smith attempted to arrest them for starting the fire. (PROSE: The Republican's Story)

Shortly thereafter, George, Helen, Ida and Alan Mortimer were rescued from the Great Fire by the First Doctor. It is possible that, for a brief period after the First Doctor's arrival, that there were three separate incarnations of the Doctor co-existing in the same time period and in close promixity to one another. (PROSE: Doctor Who and the Invasion from Space)

In the aftermath of the Great Fire, the English Catholics were falsely accused of having started it. (AUDIO: The Glorious Revolution)

The renegade Time Lady Iris Wildthyme claimed to have been present for the Great Fire. (AUDIO: Excelis Dawns)

The Dogon arrived around the time of the Great Fire of London and a Dogon Sixth Eye was first found shortly after. (WEB: torchwood.org.uk)

As the Terileptil involvement wasn't generally known, it was widely believed that the people of London were so scared they set fire to London. Alistair Gryffen noted this as an example of events concerning the spread of fear. (TV: Fear Itself)

Behind the scenes
The date of 2 September is derived from the novelisation of The Visitation, not the serial. The novelisation's rendition of the scene in episode one where the Doctor and Nyssa are sneaking around the manor house contains a line where he claims it's the first of September. Since night falls during the course of The Visitation, it's reasonable to assume that the Great Fire occurs on 2 September.