On his four-year-old debut, Isonomy carried 124 pounds in the Newmarket Handicap on 15 April and started 2/1 favourite.
In June, Isonomy was sent to Royal Ascot where, on the first day of the meeting, he defeated the 1877 Epsom Derby winner Silvio (the 4/9 favourite) in the Gold Vase over two miles [REF].