I never realized that the British horse was an integral part of that nation's history since Roman times. But that was because I didn't go to "All the Queen's Horses: The Role of the Horse in British History," an exhibit that took place at Lexington, Kentucky's Kentucky Horse Park in 2003.
Luckily, they created a web-exhibit for us to enjoy, and chock full of info it is, too. For example, I always thought the Celts were strictly foot soldiers, but now I know that in 55 BC they used cavalry and chariots to oppose Caesar's invasion. I also know that the first wild ponies in Britain originated in North America, but walked across the joined landmasses of America, Asia and Europe to their new home. And I know that the English Thoroughbred horse was established through three individual horses: the Byerly Turk, the Darley Arabian, and the Godolphin Arabian. Most of that is from Horse History, one of the learning units this web exhibit offers.
Here's the exhibit's home page. Some artifacts and paintings are here. Teacher's guides and cool activities are here.