Babylon was an ancient city in the Mesopotamian civilization and was established in roughly 2300 BCE. Located on the Euphrates river in modern-day Iraq, this walled city was among the first major civilizations in the world and is credited with major inventions in engineering, agriculture, mathematics, and written language. Setting his stories in this ancient city allows Clason to create a certain mystique around its citizens and use archaic, biblical-style language which helps to create an authoritative tone.

The Babylonians, who did not use paper, recorded information by making indentations on large tablets of clay. Clason explains that these clay tablets, which have since been discovered by archaeologists, are a major source of historical knowledge about Babylon. To add a sense of discovery to his writing, Clason invents five clay tablets that describe the financial journey of his fictional character Dabasir.

Nineveh is one of the oldest cities in the ancient world, with its archeological remains located close to modern-day Mosul, Iraq. With its founding dating to around 6000 BCE in the Neolithic Period, or the New Stone Age, Nineveh predates Babylon by over 2,500 years.