The buildings where Larry and Palmerston work are not far from each other, so it was not difficult for the animals to stumble upon each other and start to sort things out.
Larry's career as Chief Mouser began in 2011. The family of David Cameron, the former Prime Minister of Great Britain, adopted a cat from the Battersea shelter.
In 2012, Cameron wanted to stop Larry's services, as he did not work well - he caught only one mouse. The cat was to be replaced by Freya the cat. Then there was a conflict between Larry and Freya. As a result, Larry was deprived of his post, but he remained in residence. Later, Larry and Freya found a common language.
Palmerston was hired by the Foreign Office as a mouser in April 2016. He also hails from Battersea. Previously, Palmerston was an ordinary street cat.