The city of Rome stands on the Tiber River very near the west coast of Italy. It marked the northernmost border of the territory in which the Latin language was spoken and the southern edge of Etruria, the territory in which the Etruscan language was spoken.
The dictatorss were an exception to annuality and collegiality, and the censors to annuality. In times of emergency (always military) a single dictator was elected for a term of 6 months to have sole command of the state. On a regular but not annual basis two censors were elected: every five years for a term of 18 months.
The legion formed the backbone of Roman military power.
The Romans were very much convinced that their city was founded in the year 753 BC. Rome has often been said to have been started by Romulus and Remus. It was then, tradition had it, ruled by kingss for several centuries.
Livy's version of the establishment of the Republic states that the last of the Kings of Rome, Lucius Tarquinius Superbus (superbus, "the proud") had a thoroughly unpleasant son, Sextus Tarquinius, who raped a Roman noblewoman named Lucretia. Lucretia compelled her family to take action by gathering the men, telling them what happened, and killing herself. They then were compelled to avenge her, and led an uprising that drove the royal house, the Tarquins, out of Rome to take refuge in Etruria.
The early consuls took over the roles of the king with the exception of his high priesthood in the worship of Jupiter Optimus Maximus at the huge temple on the Capitoline Hill. For that duty the Romans elected a Rex sacrorum or "king of holy things." Until the end of the Republic the accusation that a powerful man wanted to make himself king remained a career-shaking charge. (Julius Caesar's assassins claimed after they acted that they were preserving Rome from the re-establishment of an explicit monarchy.)
The people of Rome were divided into patricians and plebeians. These words have taken on such different connotations of wealth and ordinariness in modern English that they must be examined in their Roman context. The two classes were ancestral and inherited. One's class was fixed by birth rather than by wealth, and though patricians had in the early Republic monopolized all political offices and probably most of the wealth, there are always signs of wealthy plebeians in the historical record, and many patrician families had lost both wealth and any political influence by the later Republic. One could move from one class to the other by adoption, as did the political operator Clodius, who managed to have himself adopted into a plebeian branch of his own family for political purposes in the late Republic, but this rarely occurred. By the 2nd century BC the classifications had meaning predominantly in religious functions - many priesthoods remained restricted to patricians.
The relationship between the plebeians and the patricians sometimes came under such a strain that the plebeians would secede from the city - they literally left the city, took their families and movable possessions, and set up camp on a hill outside the walls. These secessions happened in 494, 450, and around 287 BC. Their refusal to co-operate any longer with the patricians led to social changes on each occasion. In 494 BC, only about 15 years after the establishment of the Republic, the plebeians for the first time elected two leaders, to whom they gave the title Tribunes. The "plebs" took an oath that they would hold their leaders 'sacrosanct' or inviolate during their terms of office, and that the united plebs would kill anyone who harmed a tribune. The second secession led to further legal definition of their rights and duties and increased the number of tribunes to 10. The final secession gave the vote of the Concilium Plebis or "Council of the Plebeians" the force of law - we call this a "plebiscite".
Rome's military and diplomatic successes around the Mediterranean resulted in new and unaccustomed pressures on the structures of the old city-state. While factional strife had become a traditional part of Roman life, the stakes were now far higher; a corrupt provincial governor could enrich himself far beyond anything his ancestors imagined possible, and a successful military commander needed only the support of his legions in order to rule vast territories. In addition, small landowners were displaced in favor of large slave-run estates, resulting in large numbers of unemployed urbanites.
Beginning with the agrarian reform of Tiberius Gracchus in 133, the political convulsions became more and more severe, resulting in a series of dictatorships, civil wars, and temporary armed truces during the next century. Much of the political record of this period has survived, and we are able to understand it in some depth.
Gracchus' reform was simply to put more land in the hands of veterans, but ominously, his Senatorial opponents responded to his political machinations by killing him in the street. His younger brother Gaius Gracchus continued the reform efforts, promoted the extension of the franchise to all the cities of Italy, and established the equites as a new force in Roman politics.
A conservative reaction brought power back to the Senate, but they prosecuted the Jugurthine War of 112-105 so poorly, on top of a Slave War in Sicily, and losses at the hands of Germanic tribes, of whom the Cimbri destroyed consular armies at Arausio in 105. Rome was saved by Marius, who held multiple consulships 103-101 while defeating the Teutones at Aquae Sextiae (102) and the Cimbri near Vercellae in the following year. But Marius' military reforms had resulted in an army of proletarian volunteers with no special love for the Senate, and Marius' political allies used the army to threaten the Senate into passing laws reducing the Senate's power. Marius curbed his own allies, and took himself into lesser positions.
Again the Senate proved itself unequal to its role, and failed to deal with the growing discontent of the allies in Italy. After the reformer Livius Drusus was assassinated in 91, almost all of the Italian allies of Rome rebelled in what the Romans called the Social War (allies = Socii, related to the English "associates"). The Romans were only able to end the war in 88 by granting citizenship to all Italians living south of the Po River.
At the same time, Mithridates VI of Pontus overran Bithynia, the latest of several provocations which, this time, forced Rome to act. But Marius and Sulla contended over the command of the army, ending with Sulla marching on Rome with several legions, outlawing his opponents and passing laws favoring the Senate. Sulla then went to Greece, defeated Mithridates at Chaeronea in 86, then returned in 83 to overthrow Marius' ally Cinna. In the following year, Sulla secured appointment as dictator and used the post to reduce the power of the tribunes and the army, although the changes did not long survive his voluntary retirement in 79.
Spartacus was a Thracian slave, and was trained as a gladiator. In 73 BC he and some of his comrades rebelled at Capua and fled towards mount Vesuvius. The rebel numbers quickly grew to about 70,000, comprising mainly Thracian, Gaul and German slaves.
Initially, Spartacus and his second in command Crixus succeeded in defeating several legions sent against them piecemeal. Once a unified command was established under Licinius Crassus who had six legions, the rebellion was crushed in 71 BC. About 10,000 slaves fled the battlefield.
The fleeing slaves were intercepted by Pompey who was returning from Spain, and 6000 were crucified along Via Apia from Capua to Rome. Although Crassus did most of the fighting against the rebels, Pompey claimed the victory. This was a source of tension between the two men.
In the final analysis, once the Romans found the right leadership the rebels were quickly defeated. This does not subtract from the achievement of Spartacus, who was able to unite a band of slaves into a fighting force capable of defeating several legions.
The whole incident showed the weakness of the Senate and the regime of the late Roman Republic.