The age of a racehorse

Whatever its foaling date in the eighteenth and early nineteenth (before 1834) centuries, a racehorse's age is given from "last grass", which was conventionally assumed to be Mayday.

The age at which horses are raced has gradually reduced. In the early days of the eighteenth century, it was rare for horses younger than 6 to be raced. Over 6-year-old horses were just referred to as aged.

Owners experimented with running 3 and 4-year-olds in the 1730s, but it did not really catch on until 1770.

The first recorded race for two-year-olds took place at Newmarket in 1769.