Today there are police officers everywhere, but in 1700 London had none at all. A few old men used to protect the city streets at night, and they were not paid very much.
About 300 years ago, London was starting to get bigger. The city was very dirty, and many people were poor. There were so many thieves who stole money in the streets that people stayed at home as much as possible.
In 1750, Henry Fielding started to pay a group of people to stop thieves. They were like police officers and were called 'Bow Street Runners' because they worked near Bow Street.
Fifty years later, there were 120 Bow Street Runner, but London had become very big and needed more police officers. So, in 1829, the first Metropolitan (or London) Police Force was started with 3000 officers. Most of them worked on foot, but a few rode horses. Until 1920 all the police in London were men.
Today, London police are quite well paid, and for the few police officers who still ride horses, the pay is even better than for the others.