In ancient Rome, a city known for its spectacular and violent entertainment, there was one sport that was even more popular than gladiator fights. Chariot racing, staged at the massive Circus Maximus arena located between the Aventine and Palatine hills, gave spectators an opportunity to watch daring chariot drivers and their teams of horses race seven laps around a 2,000 foot-long sand track, where they hit top speeds of close to 40 miles per hour on the straightaways and jostled wheel-to-wheel as they hurtled around hairpin turns.

When the winning charioteer finally crossed the finish line, his victory was announced with the blast of a trumpet, and he ascended to the judges’ box, where he received a palm branch, a wreath and prize money. Then he took a quick victory lap, before the next of the day’s 24 races began, as Northern Illinois University archaeologist and art historian Sinclair Bell describes.

It was the ancient version of NASCAR, except that it was a lot more dangerous. Chariot crashes were frequent, with teams of attendants on hand to rush onto the track and clear away the wreckage and injured drivers while the race continued.

“Organized chariot racing had an enduring appeal to the Romans,” says David Matz, a professor and chair of classics at St. Bonaventure University, and author of numerous books on the ancient world, including Ancient Roman Sports, A-Z: Athletes, Venues, Events and Terms.

In legend, the sport dates back to the city’s founder, Romulus, who supposedly oversaw the construction of the first racetrack, the Circus Maximus, in the 6th century B.C. The contests went on to become not just the most popular sporting event in ancient Rome, but a deeply embedded part of Roman culture that lasted for centuries.

Over time, the races developed into an elaborate ritual that was infused with the Roman religion. According to Bell, the event began with a sacred procession through Rome’s streets, which included statues of a dozen different Roman gods, along with dancers, musicians, temple attendants and the drivers themselves. Eventually the parade reached the Circus Maximus, while 200,000 or more spectators were already waiting.

Then the focus shifted to the 12 starting gates, and the teams of two- or four-horse chariots waiting to compete. The game’s sponsor, from a platform above the starting line, dropped a white handkerchief onto the track. The gates opened, and the racers burst onto the track, and quickly began battling for the inside position that would give them an edge.

“Successful charioteering required a combination of physical strength and endurance, skill in implementing various racing strategies, and superb horsemanship,” Matz says. “Most races featured quadrigae—four-horse chariots, with the horses yoked four abreast. These specially bred horses were powerful animals, high-strung and sometimes unpredictable. Managing the team in a race was likely a charioteer’s greatest challenge.”

Chariot racing wasn’t quite as gruesome as the death matches between gladiators that Romans staged for audiences. Drivers had to be phenomenally skilled and athletic just to compete. As Bell has written, they came from all over the Roman Empire—most were enslaved, freedmen or foreigners. It was rare for a driver to be a freeborn Roman citizen. Drivers had a low social status, and a Roman who became a charioteer was barred from holding public office.

Even so, the charioteers were celebrities, and sometimes even became wealthy men. One of the sport’s top competitors was a racer named Gaius Appeuleius Diocles, who began his career in A.D 122, and in the course of his 24-year career competed for all four factions and won 1,462 of the 4,257 races in which he competed. In his career, Diocles won prizes amounting to more than 35,000,000 sesterces, a denomination of Roman coinage, which based on the value of gold would amount to more than $17 million.

Some spectators probably were attracted by the ever-present chance of seeing a gory fatal crash. But the massive crowds that filled the Circus Maximus found a lot of other compelling reasons to cheer. Matz says that some spectators probably were hard-core chariot racing junkies, who could appreciate the drivers’ skill and courage.

Others, like modern sports fans obsessed with Arsenal or the New York Yankees, were fervent followers of one of the several racing teams, or factions, that were identified by their colors. That allegiance may also have been shaped by loyalty to, or fear of, whoever the current emperor was. Some Roman rulers—Caligula, Nero and Domitian, for example—were themselves intense fans, and they had their own preferred factions, Matz says.

“Chariot racing was a national pastime in which a large percentage of the population from all classes came together, by choice, for the thrill of the races,” explains Casey Stark, an assistant professor of teaching in the history department at Bowling Green State University. More than that, “It was also a place to see and be seen. Seating arrangements reinforced disparities in Roman society. The best seats went to those with rank, such as Roman senators, and wealth, and often with the event’s sponsor or the emperor watching from a private box.”

Additionally, “betting on chariot races was very popular,” Matz says. But unlike modern sports wagering, there weren’t any betting windows at the track or bookies and oddsmakers to organize the gambling. Instead, Matz explains, “a spectator might simply turn to the fan sitting next to him, and propose a wager for the next race.”

Some bettors tried to influence the outcome supernaturally. “Several curse tablets have been found near Roman racetracks, likely by people with money on the line, that were used to give their team or driver a competitive edge,” Stark says.

Others came to Circus Maximus to enjoy some people-watching, or even used it as the equivalent of a singles bar. “The Roman poet Ovid wrote a rather graphic account of a young man’s effort to attract the attention of a young lady who was seated next to him in the Circus,” Matz says. “These kinds of interactions, whether prearranged or spontaneous, were undoubtedly very common.”

Chariot racing was so popular that even after Imperial Rome fell in 476 A.D., the sport continued for a while, with the city’s new barbarian rulers continuing to hold races. It also remained popular in the eastern empire that had split from Rome, though it finally started to wane there after fans’ fanaticism reached unruly extremes. At one hotly-contested race in Constantinople in 532 A.D., fans of the Greens faction of racers got into a brawl with adherents of the Blues faction.

When authorities arrested and then tried to hang a few of the offenders, all hell broke loose. The two factions joined forces and demanded release of the captives, and when that didn’t happen, they set fire to the city’s racetrack, the Hippodrome. The infamous Nika Riot, which lasted for days, by one estimate killed as many as 30,000 people.

That catastrophe “very likely hastened the end of Roman-style chariot racing in the eastern empire,” Matz says.

But even after the sport vanished, chariot racing wasn’t forgotten. In the 1880s, it was prominently featured in General Lew Wallace’s bestselling novel Ben-Hur, which was adapted into a theatrical play that 20 million Americans saw between 1899 and 1920, with live horses running on concealed treadmills on the stage to simulate chariot racing.

Several film versions were made as well, including a 1959 Hollywood blockbuster that starred Charlton Heston. That movie’s epic chariot race required elaborate preparations, including dozens of horses who were trained to remain calm when chariots crashed into one another. It took five days to film a simulated version of the sporting spectacle that had once captivated Roman audiences.