Complex sentence: The Prix Gladiateur is a Group 3 flat horse race in France for four-year-old and above thoroughbreds run over a distance of 3,100 metres (approximately 1 mile 7½ furlongs) at Longchamp Racecourse in September.
Split into simpler sentences: The Prix Gladiateur is a Group 3 flat horse race in France for four-year-old and above thoroughbreds. It is run over a distance of 3,100 metres (approximately 1 mile 7½ furlongs) at Longchamp Racecourse in September.