May-day was a chestnut filly bred near Brandon in Suffolk by her ownerRobert Wilson, 9th Baron Berners. She was sired by Wilson's own stallion Lamplighter, a successful racehorse who won the Craven Stakes, The Whip and several King's Plates at Newmarket. May-day's dam, the Rubens mare, was an unnamed daughter of Rubens out of Tippitywitchet and was one of the outstanding broodmares of her time. Her other foals included the Ascot Gold Cup winner Camarine, The Derby winner Phosphorus and the 1000 Guineas winner Firebrand. Both Phosphorus and Firebrand were sired by Lamplighter making them full siblings to May-day.
Racing career
1833: two-year-old season
Until 1913 there was no requirement for British racehorses to have names, and many horses were known by the name of their owner or their pedigree. The filly who would become known as May-day made her first appearance as "Ld Berners's ch. f. by Lamplighter, out of Camarine's dam" in the Criterion Stakes at Newmarket on 28 October 1830. She was made the 4/1 second favourite in a field of thirteen two-year-olds, but finished unplaced behind Bentley.
1834: three-year-old season
The Lamplighter filly made her first appearance as a three-year-old in the twenty-first running of the 1000 Guineas Stakes at Newmarket on 1 May 1834. She was ridden by John Barham Day and started at odds of 6/1 in field of seven fillies for the classic over the Ditch Mile course. The field was considered a good one and the early pace was strong. Day produced the filly with a late run on the outside to take the lead inside the final furlong and won comfortably by a length from Mr Walker's filly Velocity with Amadou in third and the favourite, Rosalie, unplaced. The New Sporting Magazine described her as "a fine, racing-like mare" whose "speed and stoutness" made her a serious contender for the Oaks. Following the 1000 Guineas, Lord Berners named his filly May-day "in honour of the day of her first victory". Four weeks after her win at Newmarket, May-day was moved up in distance to contest the Oaks over one and a half miles at Epsom. She started the 7/1 third favourite against fourteen opponents. The race was delayed by half an hour by a series of false starts and the early pace was unusually slow. May-day, ridden by Frank Boyce was restrained by her jockey until the straight where she moved up on the outside and had "the appearance of a winner" when she fell heavily approaching the final furlong. May-day got to her feet but had sustained a complete fracture of her left foreleg just above the fetlock and was immediately euthanised. The race was won by the 20/1 outsider Pussy.
