Roman legion in the context of "Canaba"

The Macedonian phalanx (Greek: Μακεδονική φάλαγξ) was an infantry formation developed by Philip II from the classical Greek phalanx, of which the main innovation was the use of the sarissa, a 6-metre pike. It was famously commanded by him during the rise of Macedon and by his son Alexander the Great during his conquest of the Achaemenid Empire and his other campaigns between 336 and 325 BC.

The Macedonian phalanx model then spread throughout the Hellenistic world, where it became the standard battle formation for pitched battles. During the Second Macedonian War (200–197 BC), Roman-Seleucid War (191–188 BC) and Third Macedonian War (171–168 BC) against the Roman Republic, the Hellenistic phalanx, both the Antigonid phalanx and the Seleucid phalanx, appeared less adaptable to changing conditions on the battlefield against the more flexible Roman legions.

The War of Actium (32–30 BC) was the last civil war of the Roman Republic, fought between Mark Antony (assisted by Cleopatra and by extension Ptolemaic Egypt) and Octavian. In 32 BC, Octavian convinced the Roman Senate to declare war on the Egyptian queen Cleopatra. Her lover and ally Mark Antony, who was Octavian's rival, gave his support for her cause. Forty percent of the Roman Senate, together with both consuls, left Rome to join the war on Antony's side. After a decisive victory for Octavian at the Battle of Actium, Cleopatra and Antony withdrew to Alexandria, where Octavian besieged the city until both Antony and Cleopatra were forced to commit suicide.

The war involved some of the largest Roman armies ever seen. Both Antony and Octavian's legions were experienced veterans of previous civil wars who had fought together, many also having once served under Julius Caesar. The two did however raise their own legions separately.

In ancient Rome, imperium was a form of authority held by a citizen to control a military or governmental entity. It is distinct from auctoritas and potestas, different and generally inferior types of power in the Roman Republic and Empire. One's imperium could be over a specific military unit, or it could be over a province or territory. Individuals given such power were referred to as curule magistrates or promagistrates. These included the curule aedile, the praetor, the consul, the magister equitum, and the dictator. In a general sense, imperium was the scope of someone's power, and could include anything, such as public office, commerce, political influence, or wealth.

A legate (Latin: legatus, Classical Latin: [ɫeːˈɡaːtʊs]) was a high-ranking military officer in the Roman army, equivalent to a modern-era general officer. Initially used to delegate power, the term became formalised under Augustus as the officer in command of a Roman legion.

From the times of the Roman Republic, legates received large shares of the military's rewards at the end of a successful campaign. This made the position a lucrative one, so it could often attract even distinguished consuls or other high-ranking political figures within Roman politics (e.g., the consul Lucius Julius Caesar volunteered late in the Gallic Wars as a legate under his first cousin, Gaius Julius Caesar).

The Battle of Pydna took place in 168 BC between Rome and Macedon during the Third Macedonian War. The battle saw the further ascendancy of Rome in the Hellenistic world and the end of the Antigonid line of kings, whose power traced back to Alexander the Great. The battle is also considered to be a victory of the Roman legion's manipular system's flexibility over the Macedonian phalanx's rigidity.

The Battle of Philippi was the final battle in the Liberators' civil war between the forces of Mark Antony and Octavian (of the Second Triumvirate) and the leaders of Julius Caesar's assassination, Brutus and Cassius, in 42 BC, at Philippi in Macedonia. The Second Triumvirate declared the civil war ostensibly to avenge Julius Caesar's assassination in 44 BC, but the underlying cause was a long-brewing conflict between the Optimates and the Populares.

The battle, involving up to 200,000 men in one of the largest of the Roman civil wars, consisted of two engagements in the plain west of the ancient city of Philippi. The first occurred in the first week of October; Brutus faced Octavian, and Antony's forces fought those of Cassius. The Roman armies fought poorly, with low discipline, nonexistent tactical coordination, and amateurish lack of command, with neither side able to exploit opportunities as they developed. At first, Brutus pushed back Octavian and entered his legions' camp. However, to the south, Cassius was defeated by Antony and died by suicide after hearing a false report that Brutus had also failed. Brutus rallied Cassius's remaining troops, and both sides ordered their army to retreat to their camps with their spoils. The battle was essentially a draw but for Cassius's suicide. A second encounter, on 23 October, finished off Brutus's forces after a hard-fought battle. He took his own life in turn, leaving the triumvirate in control of the Roman Republic.

The Praetorian Guard (Latin: cohortes praetoriae) was the imperial guard of the Imperial Roman army that served various roles for the Roman emperor including being a bodyguard unit, counterintelligence, crowd control and gathering military intelligence.

During the Roman Republic, the Praetorian Guards were escorts for high-ranking political officials (senators and procurators) and were bodyguards for the senior officers of the Roman legions. In 27 BC, after Rome's transition from republic to empire, the first emperor of Rome, Augustus, designated the Praetorians as his personal security escort. For three centuries, the guards of the Roman emperor were also known for their palace intrigues, by whose influence upon imperial politics the Praetorians could overthrow an emperor and then proclaim his successor as the new caesar of Rome. In AD 312, Constantine the Great disbanded the cohortes praetoriae and destroyed their barracks at the Castra Praetoria.