Complex sentence: A derby is a type of horse race, named after the Epsom Derby, still run at Epsom racecourse, England, which was in turn named for Edward Smith-Stanley, 12th Earl of Derby, who inaugurated the race in 1780.
Split into simpler sentences: A derby is a type of horse race, named after the Epsom Derby, still run at Epsom racecourse in England. It was in turn named for Edward Smith-Stanley, 12th Earl of Derby, who inaugurated the race in 1780.