By Pat Lowinger
The Roman Republic effectively ended on January 16, 27 BCE when the Roman Senate granted the title and commensurate powers of Augustus to Gaius Octavius, the adopted son of Julius Caesar. Preceding the Empire, the last body of Senators of the Roman Republic watched as strife, rivalries and ultimately civil war would act as the catalyst of this tumultuous transformation. By analyzing the writings of one of Rome’s most notable Senators, Marcus Tullius Cicero (106-43 BCE), we can attempt to better understand these events. In his letters, Cicero is keen to point to the failings of the Roman State, and what he believes to be the roots causes; the first being the influence of the military and the popularity of its leaders. This was closely followed by the corruption of the Senate, and lastly, the formation of the Triumvirate in 59 BCE.
Marcus Tullius Cicero (in his later years). Statue dated to 2nd Century AD on display at Ashmolean Museum of Art and Archaeology, U.K.
The 1st Century BCE had presented many difficulties for the Republic, not the least of which was the civil unrest following the Social Wars (90-88 BCE). Rome’s allies, who contributed greatly to Rome’s military and economic strength revolted. According to Appian, this revolt was in response to unequal land distribution which lead to the concentration of wealth among the Roman Aristocracy and reduced many Italians to a state of pauperism.  Shortly thereafter, in 82 BCE, Lucius Cornelius Sulla seized control of Republic and during his two-year reign as Dictator enacted a series of Constitutional reforms which placed even more power in the hands to the Aristocratic Senate. With Pompey Magnus’s defeat of Quintus Sertorius in Hispania (Spain) and Marcus Licinius Crassus’s defeat of Spartacus during the 3rd Servile War- two very popular and wealthy commanders had been able to exert considerable pressure upon the Senate. Pompey and Crassus then quickly secured key political offices for themselves. Both Pompey and Crassus were elected consul(s) in 70 BCE- setting the stage for the later conflict that would ultimately be the end of Cicero’s beloved Republic.
Rise of the Military
The reforms of the Roman military under Gaius Marius in 107 BCE changed forever the relationship the state would have with the army. The increasing territories controlled by the Republic needed a standing army to defend it. To this end, the previous requirement of land ownership was removed and all Romans of the capite censi were eligible for service. This was the formation of a professional army, equipped by the state, and motivated by the promise of pay, loot and a considerable pension. Cicero was aware of the power which a charismatic leader could exert over their troops; this was evident in 76 BCE, when Pompey had initially been denied tenure as proconsul of Hispania by the Senate. Rather than accept the Senate’s decision, Pompey refused to disband his legions- in light of this display of military power the Senate reversed their earlier decision and Pompey was appointed to proconsul. In effect, Pompey had nullified the Senate’s lawful decree by threat of military force. Pompey had shown not only his willingness, but his ability to defy the Senate. By 62 BCE, Cicero embarked on an attempt to ingratiate himself with Pompey as had other key members of the Senate:
For you have given us that strong hope of peace, of which, in sole reliance on you, I was assuring everyone. But I must inform you that your old enemies- now posing as your friends- have received a stunning blow by this dispatch, and, being disappointed in the high hopes they were entertaining, are thoroughly depressed. Though your private letter to me contained somewhat slight expression of your affection, yet I can assure you it gave me pleasure. 
Whether genuine or more likely duplicitous, by 54 BCE Cicero was presenting the case to Julius Caesar that Pompey was attempting to usurp power, possibly going so far as assuming dictatorial powers:
Cicero greets Caesar, Imperator. Observe how far I have convinced myself that you are my second self, not only in matters which concern me personally, but even those which concern my friends. It had not been my intention to take Gaius Trebatius with me for whatever destination I should be leaving town, in order to bring him home again honored as much as my zeal and favor could make him. But when Pompey remained at home longer than I had expected, and a certain hesitation on my part (with which you are not unacquainted) appeared to hinder, or at any rate retard, my departure. 
Marble bust of Gnaeus Pompeius Magnus (Pompey the Great). Ny Carlsberg Glyptotek- Copenhagen, Denmark
Pompey, as governor of Hispania, and simultaneously holding the office of praefectus annonae (controller of Rome’s grain supply) was concentrating his power. Additionally, rather than return to Spain, Pompey had opted to rule the province in absentia- remaining in Italy. Cicero makes no effort to conceal his suspicions of Pompey’s motives in his letters to Caesar. Ironically, five years later (49BCE), Cicero would be railing against Caesar’s famous crossing of the Rubicon and framing Pompey as the best hope of the Republic against this apparent grab at power. Cicero laments his failure to avert Caesar’s actions, “for on both sides there are those who desire to fight. The long and short of it is that Caesar himself- once our friend- has sent the Senate a menacing and offensive dispatch, and is so insolent as to retain his army and province in spite of the Senate.”  The Senate was no longer able by law or custom to prevent legions from entering Rome.
Corruption of the Senate
Cicero walked a fine political line. Much of his politics could be considered that of a pro-constitutionalist, allied with the Optimates; the pro-aristocratic faction within Rome who were opposed by the Populares. Throughout Cicero’s work(s), particularly those written in the last year of his life called upon ‘true Romans’ to put aside their own interests and to seek justice within the law (as codified within the Roman Constitution):
This contempt of the mind for outward fortunes thus excites great admiration; and most of all, justice, for which one virtue men are called good, seems to the multitude a quality of marvelous excellence, – and not without good reason; for no one can be just, who dreads death, pain, exile or poverty, or who prefers their opposites to honesty. Men have, especially, the highest admiration for one who is not influenced by money; for they think that the man in who this trait is made thoroughly manifest has been tested by fire. Thus justice constitutes all three of the requisites which I have named, -affection because it aims to do good to the greatest number, and for the same reason, confidence and admiration, because it spurns and neglects those things to which most men are drawn with burning greediness. 
With that said, Cicero’s own correspondence betrays his nature and through him the political nature of the Roman Senate. Perhaps Gaius Sallustius Crispus (86-35 BCE), a contemporary of Cicero stated it most succinctly; “Fortune turned against us (the Senate) and brought confusion to all we did. Greed destroyed honor, honesty and every other virtue, and changed: a government which had once surpasses all other in justice and excellence now became cruel and unbearable.”  Cicero decries what he sees the degeneration of the Senate, legal injustice(s) and corruption of the restored tribunes:
There never was a seedier lot round a table in a gambling hell. Senators under a cloud, equites out at elbows, tribunes who were not so much made of money as “collectors” of it, according to their official title. However, there were a few honest men in the panel, whom he had been unable to drive off it by rejection, and they took their seats among their uncongenial comrades with gloomy looks and signs of emotion, and were keenly disgusted at having to rub elbows with such rascals. 
During the consulships of Crassus and Pompey, the powers of the tribunes were restored. This placed both Crassus and Pompey in opposition to the pro-aristocratic powers which had been enacted by Sulla. In 59 BCE, Julius Caesar formed a political alliance with Crassus and Pompey (commonly referred to as the First Triumvirate). While informal, each of the men agreed to support each other and ensure control of the Senate while supporting their own personal agendas. Opposition to the Triumvirate appeared initially stiff, but quickly dissipated- followed by Cicero’s own reversal concerning the Optimates and his outward support of Pompey (in 54 BCE):
If I had seen the Republic in the hands of bad or profligate citizens, as we know happened during the supremacy of Cinna, and on some other occasions, I should not under the pressure, I don’t say of rewards, which are the last things to influence me, but even of danger, by which, after all, the bravest men are moved, have attached myself to their party, not even if their services to me had been of the very highest kind. As it is, seeing that the leading statesman in the Republic was Pompey, a man who had gained this power and renown by the most eminent services to the state and the most glorious achievements, and one of whose position I had been a supporter from my youth up. 
Bust of Gaius Julius Caesar- Vatican Museum, Italy.
The Triumvirate ended in 53 BCE with the death of Crassus. In 52 BCE, Pompey would be elected as the sole Consul of Rome, thus setting Caesar and Pompey on the collision course Cicero had earlier encouraged, “I have numberless witnesses to the fact that I warned Pompey not to form a union with Caesar, and afterwards not to sever it. By this union I saw the power of the Senate would be broken, by its severance a civil war would be provoked.”  In the opening days of the civil war, Cicero would place his support behind Pompey and Senate- “And he (Caesar) says that he is doing all this “to support his honor”! How can there be any “honor” where there is no moral right? Can it be morally right to have an army without commission from the state?”  As Caesar enters Rome, Cicero chides those Senators who rally to Caesar, “Ye Gods! Optimates indeed! See how they are rushing to meet Caesar, and parading their loyalty to him!” 
Being ever mercurial, as Pompey prepares to flee Italy; Cicero would again prepare to shift his support, “I may add that he (Pompey) has acted in every case against my counsel and advice. I put out of the question the old scores: how he fostered Caesar against the Republic, promoted, armed him; assisted him in the passing of laws by violence and against auspices; supported the addition of farther Gaul to his provinces; married his daughter.”  Following Pompey’s defeat, and Caesar’s rise to power, Cicero shifts again and in 45 BCE entertains Caesar at his residence. Four months later (44 BCE), Caesar would be assassinated- an act Cicero would herald as “a fine piece of work.” 
As attested to in his writings, Cicero was a complex and skilled politician- keenly observing the shift in power from the Senate to the military and by extension their populist commanders. Through inaction, impotence or corruption of the Senate the Republic was irrevocably set its course towards Empire. The bureaucracies which had served the Republic so well were ultimately unable to contend with the influx of new territories and the bureaucracies needed to govern them. Cicero’s concerns were embodied by the formation of the First Triumvirate.  Cicero and it appears other Senators, had attempted to ensure the status quo by reliance upon political intrigue and feigned patronage. The Republic, weakened by its own social disparity was not prepared to deal with the concerted effort and alliance(s) of popular military commanders. Perhaps, the duplicitous and self-serving nature of many aristocracy ultimately fostered an environment in which a populist dictator could offer a more socially equitable and less chaotic form of government.
Citations & References:
Appianus, and John M. Carter. The Civil Wars. London: Penguin Books, 1996.
Cary, M. and H. H. Schullard. A History of Rome. Third Edition. New York: St. Martin’s Press, 1975.
Cicero, Marcus Tullius., and Evelyn S. Shuckburgh. The Letters of Cicero: The Whole Extant Correspondence in Chronological Order. London: Bell, 1912.
Cicero, Marcus Tullius., Miriam T. Griffin, and E. M. Atkins. On Duties. Cambridge: Cambridge University Press, 1991.
Gaius Sallustius Crispus. The Sallust Anthology: The Catiline Conspiracy and The Jugurthine War. 1st ed. Texts from Ancient Rome Book 9. Www.bybliotech.org.
 Appian, Civil Wars, p. 1.7-9.
 Cic. Fam. 5.7
 Cic. Fam. 7.5
 Cic. Fam. 16.2
 Cic. Duties. 11
 Sallust. The Catiline Conspiracy and Jugurthine War, p. 37
 Cic. Fam. 1.16
 Cic. Fam. 1.9
 Cic. Fam. 6.6
 Cic. Fam. 7.ii
 Cic. Fam. 8.16
 Cic. Fam. 8.3
 Cic. Fam. 14.12
 Cic. Fam. 6.6-8