Tiberius and Gaius Gracchus were two Romans of noble heritage who attempted to pass land reform legislation and other measures to even the wealth disparity in Rome. Obviously, both were very unpopular with patrician classes, especially as their demonstrations had the habit of turning into angry mobs. While each brother was murdered (first Tiberius, then Gaius years later), their ideas and roles as champions of the common man live on. 

The primary cause of tensions between Romans and Jews during the Jewish occupation of Israel, was the refusal of the Jewish people to accept the Roman Emperor as a living deity. At the time of Roman occupation, the emperor was considered divine and all conquered peoples were expected to recognize his divinity. The monotheistic Jewish people believed this violated one of their most sacred rules, and so, refused.

The Roman society, at its heart, was divided into those with noble ancestry (Patricians) and those without it (Plebeians). Patricians tended to be the ruling class, construing most of the senate and other important positions of state. Plebeians were everyone else. However, there was definitely grey area; plebeian families looking for more legitimacy could marry into older, poorer, patrician families. Also, if a plebeian family was notable enough and rich enough for long enough, they would eventually become patricians (at least in practice).  

Helots were serfs in ancient Spartan society. They did the majority of the hard labor in ancient Sparta and, like all serfs, were bound to the land they worked on. They also greatly outnumbered the rest of the population of Sparta. They were, however, not known for their fighting prowess and were not trained in combat like a regular citizen of Sparta might be.

Patricians, in the Roman Republic (particularly the early years), were aristocrats who had significant legislative authority. They were distinct from plebeians and from less noble families in the Republic.

Helots were serfs/slaves in ancient Spartan society. Helots were owned by the state and were bound to the land. They enjoyed some privileges that slaves did not, but practically speaking they were serfs who were tied to the land. Most Helots were comprised of the defeated enemies of Sparta.

As the Mauryan empire is in India, the caste system, which serves as the foundation of Hinduism (founded in India), would be the social feature found there. The dominance of bureaucratic and landholding elites would be found in China, where a bureaucracy based off Confucian civil service examinations had been established. Persia, more than likely, had a benevolent posture toward minorities, as minorities were seen as low in the caste system. Finally, Rome and Greece saw the role of slavery as unusually high compared to other empires of this era.

Ancient Athens is often considered to be the prototype of western democracy. In many ways, however, it was not a very inclusive society (by modern standards). In order to vote an individual had to be free (as in, not a slave); an adult; a native of Athens (so no immigrants); and male. Only a tiny fraction of people living in Athens had any say in the character and direction of government.

In ancient Athenian society, only free, native, citizens of the city could vote. The immense wealth and power of Athens, however, attracted immigrants from all around. Metics were free, foreign-born residents of Athens. They enjoyed most of the same privileges as Athenian citizens, but could not participate in the democratic process.

The feudal system was organized with Monarchs as the primary rulers, whose rule was supported by Nobles. These nobles then had retinues of knights who served as professional soldiers. Below knights were free peasants who were not tied to the land, unlike the lowest rank of society -indentured peasants or serfs.