Horses are used in Equestrian sports in the Olympiads.
An Olympiad was reckoned as a 4 year period beginning with the Olympic Games. The first games were held in 776 BC and carried until they were outlawed by Theodosius I in 396 AD. That's 293 Olympiads.
Olympiads were not held in the years of World Wars I and Two.
There have been 30 Olympiads so far. Book it.
There are the Summer and the Winter Olympics held every 4 years.
There was 18 events.
59 events were contested at the first-ever Commonwealth Games in 1930.