BC. The Battle of the Caudine Forks showed the clumsiness of the Roman phalanx against the Samnites. The Romans had originally employed the phalanx themselves but gradually evolved more flexible tactics. The result was the three-line Roman legion of the middle period of the Roman Republic, the Manipular System. Romans used a phalanx for their third military line, the triarii. These were veteran reserve troops armed with the hastae or spear. Rome conquered most of the Macedonian successor states, along with the various Greek city-states and leagues. As these states ceased to exist, so did the armies which used the traditional phalanx. Subsequently, troops from these regions were equipped, trained and fought using the Roman model. A phalanx formation called the phoulkon appeared in the late Roman army and Byzantine army. It had characteristics of the classical Greek and Hellenistic phalanxes, but was more flexible. It was used against cavalry more than infantry. However, the phalanx did not totally disappear. In some battles between the Roman army and Hellenistic phalanxes, such as Pydna (168 BC), Cynoscephalae (197 BC) and Magnesia (190 BC), the phalanx performed well. It even drove back the Roman infantry. However, at Cynoscephalae and Magnesia, failure to defend the flanks of the phalanx led to defeat. At Pydna, the phalanx lost cohesion when pursuing retreating Roman soldiers. This allowed the Romans to penetrate the formation. Then, Roman close combat skills proved decisive. The historian Polybius details the effectiveness of the Roman legion against the phalanx. He deduces that the Romans refused to fight the phalanx where the phalanx was effective, Romans offered battle only when a legion could exploit the clumsiness and immobility of a phalanx. Spear-armed troops continued to be important elements in many armies until reliable firearms became available. These did not necessarily fight as a phalanx. For example, compare the classical phalanx and late medieval pike formations. Military historians have suggested that the Scots under William Wallace and Robert the Bruce consciously imitated the Hellenistic phalanx to produce the Scots' schiltron ("hedgehog"). However, long spears might have been used by Picts and others in Scotlands' Early Middle Ages. Prior to 1066, long spear tactics (also found in North Wales) might have been part of irregular warfare in Britain. The Scots used imported French pikes and dynamic tactics at the Battle of Flodden. However, Flodden found the Scots pitted against effective light artillery, while advancing