In 1768, Philip Astley stood atop a galloping horse. With one foot on its back and the other on its head, the former cavalry officer brandished his sword as the stallion thundered around England’s first circus ring – a roped circle in the open air on fields just south of London’s Westminster Bridge.

Astley's Amphitheatre in London.

Jump forward nearly 250 years and I’m in a big blue tent just outside Norwich. Perhaps nowhere better exemplifies the past, present and future of circus than in Britain’s oldest purpose-built circus building, the Great Yarmouth Hippodrome It’s an enormous space, with twice the seating capacity of the average provincial theatre – and it’s packed. At its centre, three Chinese girls are pedaling pushbikes furiously around a shiny, wooden-floored ring. As one, they suddenly leap from the pedals and stand atop their bikes, one foot on the saddle, the other on the handlebar, their arms held aloft in a star shape as they continue in a circle. The image is so evocative of Astley that I can almost hear the pounding of the hooves.

When Earl Chapin May wrote his 1932 survey of American circuses, From Rome to Ringling, he described the art form as “ever changing, never changing.” When I embarked on a journey through Britain’s circuses for my new book Circus Mania, I found the world of circus as ever changing and never changing as ever. The word circus itself dates from ancient Rome where the Circus Maximus and Circus Flaminus played host to chariot races, gladiators, staged battles, jugglers, acrobats and exotic animals.

To walk into a big top is to enter a timeless world where the past and present co-exist. I could be right back in the Alhambra Theatre in Leicester Square, in 1861 when French trapeze pioneer Jules Léotard (after whom the garments are named) – immortalised in George Leybourne’s song ‘The Daring Young Man On The Flying Trapeze’ – made his London debut above the heads of astounded diners.

In one ring, I find two of the funniest comedians in Britain. Former Tiswas star Clive Webb, dressed as a ringmaster, and his son Danny Adams, who sports the red nose and multi-coloured suit of a clown, have a seaside audience in stitches with their razor-sharp verbal sparring. But when they launch into a comedy boxing match, I recognise their outsize, disc-like gloves from a photograph in From Rome to Ringling. The routine was described as “an old and sure-fire routine,” even in 1932. Many of Clive and Danny’s slapstick routines have their roots in the work of Joseph Grimaldi, the 19^th-century pantomime star regarded as the Father of Clowning. Clowns are still nicknamed Joeys in his honour.