World War IV

World War IV was a war fought on Earth prior to the 25th century which affected London. Vicki Pallister noted that there had been four World Wars in London's history by that time and that St Paul's Cathedral still stood in the 25th century, having survived the four World Wars as well as the 22nd century Dalek invasion. (CC: Frostfire)

It was the last world war on Earth until the 49th century, which saw the outbreak of World War V. (BFA: Singularity)