The Romans invented concrete in the latter years of the Roman Republic. The Romans developed concrete from volcanic ash and slaked lime; an innovating that allowed the Romans to construct monumental buildings that have stood the test of time.

The Julian Calendar was created by Julius Caesar, and his scientific advisors, in 46 BCE. The Julian Calendar was incredibly reliable and was in continuous use for another 1,600 years before it was replaced by the slightly more accurate Gregorian Calendar.

A codex is a stack of pages bound together to form a rudimentary book. The invention of the codex encouraged literacy in the Roman Empire by making information more accessible and easier to disseminate.

Tiberius and Gaius Gracchus were brothers and were both populares politicians in the Roman Republic in the second century B.C.E. Populares were politicians who relied on the support of the people, particularly plebeian assemblies, to gain power in the Roman Republic. Populares were generally opposed by optimates (who served the conservative interests of the patricians). Tiberius and Gaius two of the more prominent populares in Roman history. They both served as tribune and were both murdered for their attempts at reforming Roman society and improving the lives of the common people.

Gaius Gracchus, like his brother Tiberius Gracchus, was a populares politician in the Roman Republic in the second century BCE. Like his brother, he attempted to reform aspects of Roman society so as to provide more power and equality for the poor. He is most notable for his failed attempts at addressing the problems of citizenship in the Roman Republic. He attempted to extend Roman citizenship to all Latin people living on the Italian peninsular, as well as to assorted peoples within the territory of the Roman Republic. These proposals were condemned, even by the Roman plebeians, who had no interest in sharing rights and privileges with the rest of the Roman Republic. Gaius, like his brother Tiberius, was eventually murdered by political factions opposed to his reforms. The Social War, which broke out in 90 BCE, was primarily caused by citizenship issues in the Roman Republic and might have been avoided had Gaius Gracchus got his way.

The city of Rome grew dramatically in population throughout the history of the Roman Republic, in part as a result of small farmers being displaced by the burgeoning estates of Rome’s wealthy patricians. As large scale farming and luxury estates spread around the countryside surrounding Rome, poor small scale farmers were displaced and forced to move to Rome in search of work and a reliable income.

There were three Punic wars, fought between the empires of Rome and Carthage from 264 BCE to 146 BCE. The Second Punic War is arguably the most well-known, involving Hannibal's infamous crossing of the Alps with his war elephants. The Third Punic War ended with Rome's victory and the destruction of Carthage.

Hannibal was a Carthaginian military commander during the Second Punic War. He is often remembered as one of the finest military leaders in history. He famously led an army of elephants through the Alps and attacked the Roman Republic at the outset of the Second Punic War. Hannibal led a devastating Carthaginian occupation of mainland Italy for more than a decade before a Roman counterattack forced him to return to North Africa. He was promptly defeated by the great Roman general Scipio Africanus at the Battle of Zama.

Scipio Africanus is remembered as one of the most accomplished military commanders of all time. He was a contemporary of Hannibal and the two fought against one another in Italy and North Africa. Scipio Africanus led the army of the Roman Republic against the Carthaginian army of Hannibal at the Battle of Zama. His brilliant military strategy led to the destruction of Hannibal’s army and forced the Carthaginian government to sue for peace.

Hannibal is one of the most famous and revered generals in military history. He led the Carthaginian army in the Second Punic War. Perhaps his most famous accomplishment occurred when he led an army, including a large regiment of war elephants, through the Alps to attack the Roman Republic. Hannibal was eventually defeated by Scipio Africanus, which forced the Carthaginian government to surrender to the demands of the Roman Republic.