New Scientist has a nice article about recent research into the lineage of the thoroughbred horse. It indicates that almost all thoroughbreds descended from just 28 ancestors, with a stunning 95 percent of all male racehorses descending from a single stallion, the Darley Arabian. (To my surprise, I do actually remember reading a historical novel about the Arabian origins of the thoroughbred as a kid. In fact, I ran across it recently, while looking through old books at my parents’ house. It’s King of the Wind by Marguerite Henry.)
Although thoroughbreds are best known as racing horses, they are also the most common breed for English riders of all kinds. Due to the combination of their large size and athletic ability, they do very well in eventing, hunter/jumper shows, foxhunting, and the like. (Lots of the thoroughbreds in those ordinary uses were bred for the track, but found to be too slow.) The major drawback of thoroughbreds is that they tend to be a bit high strung, some more so than others. Some of that can be tempered with training, but not all of it.
Although my mare Tara is a thoroughbred and even a former “polo pony,” she’s definitely on the more sensible end of the continuum, happily enough. I only wish she were younger!