These beautiful animals are essential to horse racing and the breeding of them is a multi-million pound industry; with the most prized animals being worth small fortunes. Because the best horses have been prized for generations, there are detailed “family” records (see below) enabling the lineage of modern day thoroughbreds to be traced back a surprisingly long way back in time.

Another surprising fact is that all thoroughbreds can trace their ancestry back to one of 3 stallions. These were:

  • The Byerly Turk – This is the oldest of the three founding stallions, apparently a warhorse that was captured by a Captain Byerly and believed to have been foaled in 1684.
  • The Darley Arabian – This is thought to be the ancestor to over 95% of thoroughbreds according to an article in the New Scientist way back in September 2005. This particular horse was purchased by Thomas Darley in Syria before being shipped back to England and being put out to stud (alright for some!)
  • The Godolphin Arabian – Named for the purchaser, this horse is supposed to be able to be traced to the legendary Seabiscuit.

Less is known about the mares involved, and due to the mechanics of the birds and the bees (and the horses), a prime stallion can mate with multiple mares, where as a mare will take ~11 months to give birth.

The guardians so to speak of the thoroughbred are Weatherbys Limited. They maintain, and have done so since 1793, The General Stud Book (GSB), which records all thoroughbred births and matings in the UK and Ireland. Weatherbys does more than just maintain this record, it also acts as the administrator for the British Racing Industry, maintaining records of ownership, names of horses, colours, and much more. In addition to this, there are other Stud books specialising in other geographic territories, such as the American Stud Book.

Over the years, the races have changed, and with the carefully managed breeding programs, the thoroughbreds have changed along with it, with dominance switching between the different bloodlines over time.