Marcus Aurelius is considered a beneficent leader, in part, because he attempted to outlaw gladiator games; finding the violence grotesque and wasteful, but when the empire was threatened by revolt he put them down by force and kept the empire united.

All wars in Roman history were considered defensive wars by their own people.

"The Meditations" was only published long after Aurelius died; he had no intention of ever publishing it, serially or otherwise.

Slavery was an important part of the Roman economy, Marcus Aurelius did not outlaw slavery.

Marcus Aurelius did not return far-flung provinces of the empire over to self-rule.

Hattusa was the capital city of the Hittite empire in what is today central Turkey.

One of the first capitals of Mayan civilization was El Mirador.

The Babylonian empire's capital was Babylon itself.

Over 3000 years of self-rule, the Egyptian empire had different capital cities, most notably Memphis; Hattusa was not a capital under the Egyptian empire.

The eastern Roman empire was centered in Constantinople, what is today officially Istanbul.

The Hellenistic Empire is the name given to the massive territory conquered by Alexander the Great in the fourth century B.C.E. Alexander, ruler of the Macedonian Kingdom, conquered much of the known world from Egypt all the way to the Indian subcontinent. But, after his death, his conquests were divided between the surviving generals of his campaign. This divided territory is collectively called the Hellenistic Empire. 

Following the untimely death of Alexander the Great in 323 B.C.E. his massive empire was divided between his most powerful generals. The Seleucid Empire was one such Hellenistic state that was established by Seleucus I Nicator in 312 B.C.E. The Seleucid Empire ruled over much of the former Persian Empire - stretching from Mesopotamia to India.

Augustus Caesar was one of the most accomplished and esteemed rulers (and emperors) in the history of Rome. He expanded Roman territory in Iberia, Germany, southeastern Europe, North Africa, and the near-east. He did not, however, conquer the British Isles. The Roman conquest of Britain was completed in waves, beginning with Emperor Claudius in 43 C.E. and completed with the construction of Hadrian's Wall in the second century C.E.

The Persian Royal Road was built during the fifth century B.C.E. under the orders of the Persian Emperor Darius I. The road was constructed to allow Darius to better administer his vast empire, to encourage trade and facilitate the movement of armies from one part of the empire to another.

The Olmec civilization was the first major civilization to arise in Mexico, in Central America. The Olmecs arose during the Mesoamerican Neolithic Revolution in the first millennium before the common era. They are considered to be the forerunners of the later Mayan and Aztec civilizations.

The murder of Julius Caesar, at the hands of senators in the Roman Senate, led to a civil war that paved the way for the rise of Augustus Caesar and the Roman Empire.

A Roman Triumph was a public parade or monument undertaken or constructed to honor a successful military commander and to celebrate his territorial conquests. It was an important part of social life in the city of Rome and a useful political tool for would-be consuls, dictators, and emperors.

The Achaemenid Empire was formed by Cyrus the Great in 552 BCE It is considered the prototype of the later, much larger, Persian Empire.