Undoubtedly, there was chaos leading up to the regime change at the end of the 1st century BCE, but there were a few particular reasons that led to “orgy of bloodshed” at the end of the Republic.
First of these were the consequences of expansion: Rome was originally meant to be an agrarian society, with a flexible political system aiming to strike a balance between personal freedom and senatorial control. However, Roman expansion into Carthage, the Hellenistic world, and other Mediterranean territories created increased strain on Roman society as Romans found that their farmer-soldiers and agrarian economy could no longer bear the brunt of the increasingly lengthy wars across wider-ranging areas. In addition, the influx of wealth and resources due to military success held the potential to be a key to prosperity, but instead threatened to fundamentally transform the Roman system both economically and politically. Politically, many Roman elites used their military success as a tool to pursue more glorias and wealth. The pursuit of these virtues soon created a competition amongst Roman officials and many decided to wage war without Senatorial approval. Such selfish actions highlighted the difficulty of controlling ambitious nobles and sowed the seeds for Rome’s eventual destruction. Economically, Roman expansion facilitated the creation of the equites. These people of equestrian ranks were normally merchants who possessed extreme wealth but lacked the political influence of people from the senatorial class. The plundering of cities such as Carthage and Corinth assisted the rise of this new social class, and they played a crucial role in Roman society in the late Republic. The creation of this new class ripped away the facade of Roman wealth and glory and revealed the ugly truth of Roman expansion- the riches brought to Rome were unevenly distributed, and increased expansion brought about increased class divide, which paved the way for explosive, future conflicts.
Secondly, in addition to division amongst different classes, there were also mounting pressures between members of the same class. One prominent example of this divide happening were the Gracchi reforms. When Tiberius Gracchus was elected as Tribune of the Plebs in 133 BCE, he aimed to alleviate social tensions by redistributing state-owned land (ager publicus) to poorer citizens. Tiberius sought to “confiscate all land held in excess of the limit”, which was set at 500 iugera (312.5 acres) per citizen. The confiscated land would then be divided among relatively less affluent people in locks of 30 iugera or 20 acres. His policies, however, achieved the opposite effect of what it intended to achieve: instead of lowering social pressure, the policies heightened them and aroused intense fear within people of the same senatorial class as Tiberius. The policies were highly opposed by the senatorial nobility, who were the main holders of the land that were to be confiscated. Tiberius then used his tribunal powers, invoking the “legislative power of the tribune” , and turned to the Concilium Plebis, the Popular Assembly. This, although not illegal, was unprecedented, and soon after his Lex Sempronia agraria was passed by the Assembly and became law, Tiberius was murdered by a senatorial mob who feared that he desired personal power and was trying to challenge the whole social order of the Republic. His younger brother, Gaius, tried to revitalize these agrarian reforms, but he too was beaten to death. These events showed the beginning of the total collapse of orders as Romans started turning against themselves- the aggravation of these conflicts were the direct causes of the collapse of the Republic.
Thirdly, besides internal dissent within the Republic, Rome was also facing wars on almost all fronts that eventually proved unsustainable for the Republic. Throughout the whole history of the Republic, Rome found itself constantly at war with nearby countries. At the end of the Republic, Rome fought the Jugurthine war in Numidia, the Cimbrian War in Germany, and three Mithridatic Wars. There were also conquests in Gaul and parts of Brittania. Although these wars drained Rome;s resources, Rome found itself almost always victorious. The real warfares that dismantled the society were the internal warfares, such as the Social War, which was fought against residents of the Italian Peninsula, the Servile Wars, which were fought against slaves, the war against Catilina, which was a war fought in response to the Catilinarian Conspiracy. Roman historian Sallust later commented on the latter, saying how the Roman people “did not attain a joyful or bloodless victory” and the most energetic fighters had been “killed in battle” ot “returned gravely wounded”. These wars were a culmination of the anger within the Republic, and proved to everyone that Rome was in utter anarchy. The wars also slaughtered many elite Roman soldiers and depleted Roman riches. Things soon escalated as more violent civil wars broke out between the aforementioned Cornelius Sulla and Gaius Marius (which Sulla won due to his victory at the Battle of Mount Tifata), Caesar and Pompey, and Mark Antony and Octavian. All of these wars drained Rome’s economic and human resources, and corrupted the moral ideals that the Republic rested on. These events also proved that the Republican democracy and system of governance was unworkable for a rapidly-growing society, and change was required for Rome to survive.