A Roman cavalryman's emergency brake
A cavesson, also known as a Psálion, was a Roman or Thracian cavalryman's emergency brake. "Its lower curved bar was connected to a lead rope attached to the saddle or wrapped around the rider's arm. The cavesson presses on the horse's nose, a very sensitive area, and is used for reprimanding a spirited horse, or simply keeping some control of it, when the rider has to let the reins go for fighting. It was also used for leading a horse on foot. On this example, the long angled shanks have a leverage effect increasing the strength of the rider's action on the nose (like today's hackamores)." - Metropolitan Museum of Art Developed as early as the 5th century BCE, it is described in the equestrian treaty of Xenophon (ca. 430-355 BCE). Examples have been found throughout western Europe and in Britain as far as Hadrian's wall. Scholars think this distribution was the result of eastern cavalrymen, particularly Thracians, serving in the Roman army. Romulus ...