Time line of Roman History before 1AD.

753 BC According to legend, Rome was founded by Romulus.
387 BC In 387 BC Ancient Rome is sacked and looted by the Gauls, a neighboring empire.
367 BC In 367 BC plebeians, the lower class, gained the right to be consuls, the two chief magistrates. These Consuls were elected annually.
343 to 290 BC In the period of 343 to 290 BC, the Romans conquered the Sabines to the North, and the Samnites to the South East.
280 BC In 280 BC many Greek cities in South Italy were taken by Rome.
264 to 241 BC In 264 to 241 BC Rome fought Carthage in the First Punic War. Rome won, gaining Sicily.
238 BC In 238 BC Sardinia was taken from Carthage.
226 to 222 BC From 226 to 222 BC Rome battled against Gauls. The Second Punic war erupts. Carthage is invaded from Spain, and Hannibal came over the Alps with his elephants. Most of his army died on the way over the Alps. His elephants became a disadvantage, as Roman legion would use drums and trumpet to scare the elephants in turning and trampling their own people.
202 BC In 202 BC General Scipio Africanus destroys Hannibal at Zama. Carthage gives up its Spanish colonies.
149 BC In 149 BC the Third Punic war begins.
146 BC 146 BC: Greece became in effect a Roman province. Carthage was destroyed and its territory taken.
91 to 88 BC From 91 to 88 BC: There is a civil war in the Empire. Italians want all inclusive citizenship to the Roman Empire.
60 BC 60 BC: The First Triumvirate was formed. This is an alliance between Pompey and the democratic leaders Crassus and Caesar. This further unifies the Roman Empire.
51 BC In 51 BC: Caesar conquered Gaul as far as the Rhine. Caesar begins his dictatorship.
49 BC 49 BC: Caesar returns to Rome. Pompey's radical political party rebels against Caesar's rising power, and a civil war begins.
48 BC 48 BC: Pompey is defeated by Caesar.
44 BC 44 BC: Caesar is assassinated by members of the senate.
43 BC 43 BC: Second Triumvirate formed by Octavian, Mark Antony, and Lepidus.
32 BC In 32 BC there is a war between Octavian and Mark Antony. A year later Octavian wins.
27 BC 27 BC: Octavian took the name Augustus. He became the absolute ruler, although he took the title first citizen to prevent panic. This begins Pax Romana. (200 years of prosperity)