into battle. The Celts’ main early advantage was their ability to scare and intimidate foes on the battlefield. So even though most Celtic warriors were thus unarmored, the Celts themselves fought in the manner of heavy infantry. Using fear and shock tactics as a form of psychological warfare while closing in on enemy formations in dense masses in order to break enemy lines and rout formations. This was an incredibly successful and effective tactic at first, such as at the Battle of the Allia. Celtic peoples were also renowned for their skill as equestrians both on and off the field of battle. As horses played an important role in overall Celtic culture, with ownership being linked with both social status and wealth. Strabo even wrote that though all Gauls are great warriors by nature, they fight better on horseback than on foot, and that the best of the Roman cavalry is drawn from their number. Auxiliary Gallic horsemen were commonly used by the late Roman Republic and early Roman Empire. Having most notably fought for Crassus at the Battle of Carrhae. These Celtic mercenaries lead by Publius Licinius Crassus held their own against a superior Parthian force during the key engagement. However an ambush, the heavy armor of the Cataphracts combined with use of Horse archers and the parthian shot all contributed to their defeat. Pausanias described Celtic Cavalry tactics while recounting the Celtic invasion of Greece by Brennus and Bolgios in his Description of Greece. He described a tactic called the Trimarcisia or the "feat of three horsemen" in which each mounted Gallic warrior was accompanied into battle by two attendants who each had a horse of their own. According to Pausanias when a Gallic horsemen was injured or killed, one attendant mounted the horse in his master's place ready to continue the fight. When the first rider was only wounded, one attendant brought back the wounded warrior to camp, while the other took his place in the height of the action. The carnyx was a wind instrument of the Iron Age Celts, attested for ca. 300 BC to 200 AD. It is a kind of bronze trumpet, held vertically, the mouth styled in the shape of a boar's head. It was used in warfare, probably to incite troops to battle and intimidate opponents. The instrument's upright carriage allowed its notes to carry over the heads of the participants