Babylonia

State · 1,800–601 BCE · at its largest around 1,400 BCE

Kingdom of southern Mesopotamia centred on Babylon, made a great power by Hammurabi and later ruled for centuries by the Kassite dynasty.

On its lands while it lasted

Eridu (c. 5,400–600 BCE): Regarded by the Sumerians as the first city; its temple to the god Enki was rebuilt many times from the Ubaid period onward.
Uruk (c. 5,000 BCE – c. 700 CE): Sumerian city on the Euphrates that by about 3100 BCE was probably the largest city in the world, centre of the first urban civilization.
Assur (2,500–609 BCE): Capital of Assyria (1800 BCE–901 BCE), Neo-Assyrian Empire (900 BCE–609 BCE).
Babylon (2,201 BCE – 1 CE): Capital of Babylonia (1800 BCE–601 BCE), Neo-Babylonian Empire (600 BCE–539 BCE), Achaemenid Empire (550 BCE–330 BCE).
Hammurabi (c. 1,810 BCE – 1,750 BCE): Sixth king of the First Babylonian dynasty (r. 1792–1750 BCE), he conquered much of Mesopotamia and issued one of the best-known ancient law codes.
Plimpton 322 (c. 1,800 BCE): A Babylonian clay tablet listing numbers that correspond to Pythagorean triples, showing the sophistication of Old Babylonian sexagesimal mathematics.
Kar-Tukulti-Ninurta (c. 1,800–901 BCE): Capital of Assyria (1800 BCE–901 BCE).
Code of Hammurabi (c. 1,754 BCE): A Babylonian legal text of 282 laws inscribed on a basalt stele, known for its principle of proportional retribution; the stele was found at Susa in 1901.
Chogha Zanbil (c. 1,250 BCE): A ziggurat complex built by the Elamite king Untash-Napirisha, one of the best-preserved ziggurats in the world.
Nebuchadnezzar II (c. 642 BCE – 562 BCE): King of Babylon (r. 605–562 BCE) who rebuilt Babylon on a grand scale and conquered Jerusalem, deporting many of its inhabitants.