Competition takes place over four days (Thursday through Sunday), although the event's name says it continues to indicate a three day competition. Dressage competition is on Thursday and Friday (due to the large number of entries), cross-country is on Saturday, and show-jumping is on Sunday.
Rolex is held the last weekend of April and is the week before the Kentucky Derby.
Rolex is one of the three events in the Rolex Grand Slam of Eventing. In order to win this prestigious award the rider must win Rolex Kentucky Three Day Event, Badminton Horse Trials the first week of May, and Burghley Horse Trials the first week of September all in succession. So far the only rider to win the Rolex Grand Slam of Eventing is Pippa Funnell. The award for this is $250,000 in prize money.
In 1974, Bruce Davidson and the United States Equestrian Team won individual and team gold at the World Championships held in Burghley, England. This gave the United States the right to hold the next World Championships four years later, in 1978. The Kentucky Horse Park in Lexington, Kentucky was due to open around the same time, and plans were made to hold the World Championships there.
Equestrian Events, Inc. (EEI) was formed to as a non-profit organization to help plan the competition and raise public awareness. The first horse trials at the Kentucky Horse Park was held in 1976, to prepare. In 1977, the National Pony Club Rally and the North American Junior Three-Day Event Championships was also held there.
The 1978 event had more than 170,000 spectators and added more than $4 million to the local economy. The event was broadcast worldwide, as well as nationally on CBS. The success of the World Championships helped to convince the EEU to continue the event annually. Today, the event is broadcast worldwide in 18 languages.
Although the event began as an advanced three-day, and later included open intermediate and preliminary competitions, today it only holds the highest level: the CCI****. Intermediate-level competition was held in 1979 and from 1985-1981. An Advanced-level CCI was held from 1980-1999 up to the *** level, with Advanced Horse Trials (non-CCI) also held from 1992-1996. The CCI**** was begun in 1998, and has been held annually to this day. Since 2000, the CCI**** is the only competition held during this time, and the preliminary, intermediate, and CCI*** levels are not offered.
Rolex Kentucky had also hoped to continue the classic format, despite the other major events around the world switching to the short format. Originally, the plan was to alternate years, offering the short format in even-numbered years as preparation for the Olympic games or the World Championship, while running the classic format in odd-numbered years. However, in 2006 it was announced that, due to lack of funds and interest from upper level riders, the event would only offer the short format. Therefore, all competition run before 2005 (excluding the 2004 Modified division) was run "classic format," and the 2006 event onward will be run in the "short format."