You may be looking for Martian Invasion of 1997.

The Martian invasion of Earth was a war between Martian invasion forces and a human resistance during the late 19th century. (PROSE: The Book of the Enemy)

The invasion began on a Thursday in June of 1894, when a Martian cylinder landed in a cemetery near the Moulin Rouge, Montmartre. Iris Wildthyme, Panda, Simon, and Kelly witnessed this event, as they were dining at the Moulin Rouge at the time. Not wanting to get involved, Iris and her friends left, and shortly afterwards, Anthony Marvelle gave two Martian Time Agents front-row tickets to a Vince Cosmos concert in 1973, instructing them to assassinate Cosmos. According to this account however, these events took place in an alternate timeline, (PROSE: Enter Wildthyme) though other accounts contradicted this. (PROSE: Biography, Timothy Bold Interviews Vince Cosmos, et al.)

An earlier Iris had been instrumental in the final battles with the Martians, seven years after the initial invasion. (PROSE: Enter Wildthyme)

According to one account, the Martians were defeated by the Torchwood Institute, and H. G. Wells helped cover up the invasion by writing his novel, The War of the Worlds. (AUDIO: Goodbye Piccadilly)

According to another account, the invasion was stopped during the reign of King Edward VII, and afterwards, the Martians established an uneasy peace with Great Britain. Many in the British Empire were uneasy with allying with such recent would-be invaders, but it was generally thought slightly preferable to an alliance with the Germans. Mars' great scientists inspired a 1905 reorganisation of Russia's government into a paragon of rationality and enlightenment. Sherlock Holmes and Tom visited the Martian Embassy in Stepney.

However, the invasion and its aftermath was erased from history, along with Martian civilisation, by the action of The Book of the Enemy during the War in Heaven. After erasure from the timeline, its events were captured in the novel The War of the Worlds. (PROSE: The Book of the Enemy)

After the invasion, Martians would still be encountered by Iris Wildthyme, Vince Cosmos, and MIAOW. (PROSE: The Ninnies on Putney Common, Hang onto Yourself, Green Mars Blues, Mother, Maiden, Crone; AUDIO: Vince Cosmos: Glam Rock Detective)