Ocean Swell, like both of his parents, was bred by his owner, the Liberal politician and former First-class cricketer, Harry Primrose, 6th Earl of Rosebery,[1] at his Mentmore Stud.
[5] Ocean Swell showed little ability in the earliest part of his career, finishing unplaced in his first three starts, before running second in the Isleham Plate at Newmarket in the autumn.
On his final run of the year Ocean Swell won the six furlong Alington Plate at the same course beating a field of nineteen which included the future New St Leger winner Tehran.
[6] In a "furious" finish, Ocean Swell stayed on strongly in the closing stages, showing "pluck and stamina" to win a "great fight"[7] by a neck from Tehran, with the fast-finishing Happy Landing a short head back in third.
After the race Lord Rosebery praised his colt's speed and stamina and announced that he would stay in training with the Ascot Gold Cup as his main objective.
Tehran, who had been unbeaten since losing to Ocean Swell in the Derby was a late withdrawal: his trainer Frank Butters did not want to risk him on hard ground before the Ascot Gold Cup.
[12] The end of the war in Europe meant than some races were allowed to return to their traditional venues and on 7 July the Gold Cup was run at Ascot for the first time since 1939 in front of an estimated 60,000 spectators.