Clarissimus was a British Thoroughbred racehorse and sire. He was highly rated as a juvenile and showed promise by winning the Clearwell Stakes on the second of his two starts. He recorded his biggest when winning the 2000 Guineas on his debut as a three-year-old. Clarissimus went on to finish second in the Newmarket Stakes and a substitute St Leger before winning the Champion Stakes on his final appearance. After his retirement from racing he became a breeding stallion and had considerable influence as a sire of broodmares.
Clarissimus showed very promising form on the training gallops and was highly regarded by his trainer, but on his racecourse debut he was well beaten by the fillies Telephone Girl and Fifinella in the Bibury Stakes ant Newmarket. At the same track in October he recorded his first success in the Clearwell Stakes.
1916: three-year-old season
Clarissimus performed well in training in the spring of 1916 although his trainer's confidence was somewhat dented when his galloping companion, a filly named Angelina, ran poorly in the Greenham Stakes. On 3 May Clarissimus, ridden by Jimmy Clark, started at odds of 100/7 for the 108th running of the 2000 Guineas over the Rowley Mile course at Newmarket. The race was run in "hazy" conditions and the early stages were not clearly visible from the stands although it was clear that the horses had split into two groups on either side of the wide straight. When the field emerged into clear view Clarissimus was towards the front of the group on the stands-side and won "pretty comfortably" by three quarters of a length from Kwang-Su with Nassovian half a length away in third place. The favourite Figaro, who raced up the opposite side of the track, finished fourth of the seventeen runners. In the Newmarket Stakes over ten furlongs on 17 May, Clarissimus was beaten half a length by Figaro. He had a particularly bad race and did not recover sufficiently to take part in the "New Derby". After a break of almost four months, Clarissimus returned for the September Stakes at Newmarket, a substitute race for the St Leger. He proved to be no match for the favourite Hurry On but took second place, five lengths clear of Atheling in third place. In October the colt was matched against older horses in the Champion Stakes and started the 6/4 favourite after the late withdrawal of Pommern. Ridden by the Australian jockey Frank Bullock, he had "no difficulty" in winning from the four-year-old filly Silver Tag.
Assessment and honours
In their book, A Century of Champions, based on the Timeform rating system, John Randall and Tony Morris rated Clarissimus an "average" winner of the 2000 Guineas.
Stud record
At the end of his racing career Clarissimus was retired to become a breeding stallion in England where he stood for three years before being exported to France. Although his offspring had little success on the track his daughters had considerable success as broodmares. He was the damsire of Pharis, Brantome, Donatello and Crudite. His last foals were born in 1933.
Pedigree
Clarissimus was inbred 4 × 4 to Galopin, meaning that this stallion appears twice in the fourth generation of his pedigree.