Babylon was a city-state of ancient Mesopotamia, founded around 2300 BC, the remains of which are found in present-day Al Hillah, Babil Province, Iraq, about 85 km (55 mi) south of Baghdad. All that remains of the original ancient famed city of Babylon today is a mound, or tell, of broken mud-brick buildings and debris in the fertile Mesopotamian plain between the Tigris and Euphrates rivers, in Iraq. Babylon was a great city between the 19th and 6th centuries BC, during which it was at times the capital of successive empires of Babylonia. In 539 BC, it fell to the Persians, who maintained it as an important city of their empire. In later times, though the land remained populated and had an important place in later civilizations, the center moved to other great cities such as Baghdad, and Babylon fell into ruin, to be re-discovered by archaeologists many centuries later.
Technically, Babylon refers to a city while Babylonia refers to the larger region in which the city is situated, yet popular culture often uses the terms interchangeably. As neither entity plays a very large role in Harry Turtledove's fiction, they have not been given separate articles.
In the early 21st century, archaeological expeditions were being conducted at ancient Babylonian sites. A newspaper report on one discovery was so interesting that Lise Gimpel and Willi Dorsch temporarily found it even more exciting than bridge.
The ancient city of Babylonia had known many rulers and cultures, and under all of them retained its position as a significant regional power. The latest of these changes was when Babylon was taken over by invading Turkic tribes from central Asia, who eventually took up the militant religion of Sword Buddhism, built up a modern civilization, and became the arch-foes of the Philistinians.