The First Foot Guards
We are a Revolutionary War
reenactment group based in Boston MA,
accurately portraying the royal household regiment that is now known as
The Grenadier Guards
If you'd been in London from 1770 onwards, you might have witnessed the birth of the Circus. Certainly the Roman circus (or circle) was a place for spectacle, but there is no continuous tradition that connects the two, and the circus, as we know it today was first seen in London in the 1770s.
Philip Astley (1742-1814) was a Sergeant Major who had served in the 15th Light Dragoons in the Seven Years War. He was a remarkable horseman, and when he retired from the army he became an equestrian trick rider along with others who were popular and performed at the pleasure-gardens in London, such as Vauxhall and Ranelagh.
Astley opened a riding school in 1768 London near Westminster Bridge (this is the bridge that you see adjacent to Big Ben and the Houses of Parliament). Here he held a school in the mornings, and performed trick riding in the afternoons. He set up a ring, grandiloquently calling it "the circus." The idea of the ring was not Astley's, but the name was. His original ring was 62 feet in diameter, which he later reduced to 42 feet, which is still the standard diameter today.
By 1770, Astley's performances were more in demand than his teaching skills, and people flocked to see him perform. By 1772 The Circus needed to add some variety, so he hired jugglers, acrobats, tightrope walkers and clowns, thus inventing the format of the modern-day circus (but without wild animals). The successful format was copied by a former performer, Charles Hughes, who opened the Royal Circus. This perpetuated the name 'circus' for an entertainment of this kind.
Astley went on to even greater success, opening the first circus in Paris, the Amphitheatre Anglois. His Astley's Circus became a fixture on the South Bank of London for many years after 1772.