In 2006 Holy Roman Emperor won two Group One races, the
Phoenix Stakes where he defeated the Coventry Stakes winner Hellvelyn and subsequent Group One winning filly Miss Beatrix and the
Prix Jean-Luc Lagardère where he defeated the useful French colt Battle Paint. He also defeated subsequent three-year-old mile champion Excellent Art producing a blistering turn of foot to win the Group Two Railway Stakes at the Curragh. His greatest rival was
Teofilo, to whom he finished runner-up twice, firstly in the
National Stakes, and later in the
Dewhurst Stakes. There was great anticipation of another year of races between the pair, but it was decided in March 2007 to retire Holy Roman Emperor to stud as a replacement for
George Washington, who was suffering fertility problems (and was also a son of Danehill). ==Stud career==