Roman infantry tactics are the theoretical and historical deployment, formation, and manoeuvres of the Roman infantry from the start of the Roman Republic to the fall of the Western Roman Empire. The focus below is primarily on Roman tactics: the "how" of their approach to battle, and how it stacked up against a variety of opponents over time. It does not attempt detailed coverage of things like army structure or equipment. Various battles are summarized to illustrate Roman methods with links to detailed articles on individual encounters. The original Roman army was made up of hoplites, whose main strategy was forming into a phalanx. By the early third century BCE, the Roman army would switch to the maniple system, which would divide the Roman army into three units, hastati, principes, and triarii. Later, in 107BCE, Marius would institute the so-called Marian reforms, creating the Roman legions. This system would evolve into the Late Roman Army, which utilized the comitatenses and limitanei units to defend the Empire. Roman legionaries had armour, a gladius, a shield, two pila, and food rations. They carried around tools such as a dolabra, a wooden stave, and a shallow wicker basket. These tools would be used for building castra (camps). Sometimes Roman soldiers would have mules that carried equipment. Legionaries carried onagers, ballistae, and scorpios. Roman soldiers would train for four months. They learned marching skills first, followed by learning how to use their weapons. Then they began to spar with other soldiers. During the training exercise, the soldiers would also be taught to obey their commanders and either the Republic or the Emperor. Legions were divided into units called cohorts. Each cohort was divided into three maniples. Each maniple was divided into centuries. Several legions made up field armies. During the Republic consuls, proconsuls, praetors, propraetors, and dictators were the only officials that could command an army. A legatus assisted the magistrate in commanding the legion.