Marcus Junius Brutus in the context of "Gaius Cassius Longinus"

Julius Caesar, the Roman dictator, was assassinated on the Ides of March (15 March), 44 BC, by a group of senators during a Senate session at the Curia of Pompey, located within the Theatre of Pompey in Rome. The conspirators, numbering between 60 and 70 individuals and led by Marcus Junius Brutus, Gaius Cassius Longinus, and Decimus Junius Brutus Albinus, stabbed Caesar approximately 23 times. They justified the act as a preemptive defense of the Roman Republic, asserting that Caesar's accumulation of lifelong political authority—including his perpetual dictatorship and other honors—threatened republican traditions.

The assassination failed to achieve its immediate objective of restoring the Republic's institutions. Instead, it precipitated Caesar's posthumous deification, triggered the Liberators' civil war (43–42 BC) between his supporters and the conspirators, and contributed to the collapse of the Republic. These events ultimately culminated in the rise of the Roman Empire under Augustus, marking the beginning of the Principate era.

The Roman–Parthian Wars (54 BC – 217 AD) were a series of conflicts between the Parthian Empire and the Roman Republic and Roman Empire. It was the first series of conflicts in what would be 682 years of Roman–Persian Wars.

Battles between the Parthian Empire and the Roman Republic began in 54 BC. This first incursion against Parthia was repulsed, notably at the Battle of Carrhae (53 BC). During the Roman Liberators' civil war of the 1st century BC, the Parthians actively supported Brutus and Cassius, invading Syria, and gaining territories in the Levant. However, the conclusion of the second Roman civil war brought a revival of Roman strength in Western Asia.

Lucius Junius Brutus (died c. 500 BC) was the semi-legendary founder of the Roman Republic and traditionally one of its two first consuls. Depicted as responsible for the expulsion of his uncle, the Roman king Tarquinius Superbus after the rape and suicide of Lucretia, in the traditional accounts it is he who led the overthrow of the Roman monarchy. He was then involved in securing the abdication of fellow consul Tarquinius Collatinus, and the suppression of a plot to restore the Tarquinian monarchy.

He was claimed as an ancestor of the Roman gens Junia, including Decimus Junius Brutus and Marcus Junius Brutus, the most infamous of Julius Caesar's assassins. Traditions about his life may have been fictional, and some scholars argue that it was the Etruscan king Porsenna who overthrew Tarquinius. The plebeian status of the Junia gens has also raised doubts about his position as a consul and the alleged initial patrician domination of the office. Depicted as the nephew of Tarquinius, he may have symbolized the internal tensions that occurred during the transition between the monarchy and the republic.

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 Theatre of Pompey (Latin: Theatrum Pompeii, Italian: Teatro di Pompeo), also known by other names, was a structure in Ancient Rome built during the latter part of the Roman Republican era by Pompey the Great. Completed in 55 BC, it was the first permanent theatre to be built in Rome. Its ruins are located at Largo di Torre Argentina.

Enclosed by the large columned porticos was an expansive garden complex of fountains and statues. Along the stretch of the covered arcade were rooms dedicated to the exposition of art and other works collected by Pompey during his campaigns. On the opposite end of the garden complex was the Curia of Pompey for political meetings. The senate would often use this building along with a number of temples and halls that satisfied the requirements for their formal meetings. The curia is infamous as the place where Julius Caesar was assassinated by Brutus and Cassius during a session of the Senate on 15 March 44 BC.

Decimus Junius Brutus Albinus (27 April 81 BC – September 43 BC) was a Roman general and politician of the late republican period and one of the leading instigators of Julius Caesar's assassination. He had previously been an important supporter of Caesar in the Gallic Wars and in the civil war against Pompey. Decimus Brutus is often confused with his distant cousin and fellow conspirator, Marcus Junius Brutus.

Due to a typographical error in a 16th-century English publication, he is often known in English-speaking popular culture as Decius Brutus.