High Quality Content by WIKIPEDIA articles! The known history of the horse in Britain starts with horse remains found in Pakefield, East Anglia dating from 700,000 BC, and in Boxgrove, Sussex, dating from 500,000 BC. Early humans were active hunters of horses, and finds from the Ice Age have been recovered from many sites. At that time, the ancient Briton peninsula was attached to the continental mainland by a low-lying area now known as "Doggerland," and land animals could migrate freely back and forth between the areas that are now Britain and continental Europe. Domestication of horses in Britain, and use of horse-drawn vehicles, dates back to at least 2500 BC, and by the time of the Roman invasion British tribes were assembling armies which included thousands of war chariots.