The Chimera took control of London after flooding British Central Command with the River Thames. This left only a small force of less than 5,000 soldiers to defend the rest of the country, as the majority of Britain's military might was lost when its Royal Navy was wiped out by freak storms in the English Channel and many of its ground troops lost in the European theatre while supporting the United European Defense. By early 1951, the Chimera ferried its entire invasion forces through massive fleets of dropships to London.
Under the Chimeran occupation, the environments of London as well as the areas surrounding the city underwent several, drastic changes: the weather dropped to below freezing point that the water in Thames River become frozen solid ice, and snowstorms and blizzards would occur frequently, and as well of the unearthing of a Chimeran hub tower in the center of the city.
Sergeant Nathan Hale arrived in London just shortly after he followed the underground power conduit junction all the way from Bracknell to Chimeran tower "C-03" in London suburb of Lambeth for several miles and radioed Captain Rachel Parker that destroying the hub tower would destroy the Chimera. In the final battle of Operation Morning Star, London was retaken and liberated by joint Anglo-American military forces after the hub tower was successfully destroyed by Nathan Hale during the Battle of London on July 14, 1951. This lead to the destruction of the tower network throughout Britain and causing the Chimera to die en masse, freeing Britain from the Chimera.