The Akkadian Empire—which in 2300 BCE had…

The Akkadian Empire—which in 2300 BCE had become the second civilization to subsume independent societies into a single state (the first being ancient Egypt at around 3100 BCE)—is brought low by the wide-ranging, centuries-long drought.

The Sargonic dynasty collapses around 2180 amid a prolonged drought in the region from the Aegean to the Indus, possibly triggered by volcanic eruptions elsewhere, and invasions by two groups.

Archaeological evidence documents widespread abandonment of the agricultural plains of northern Mesopotamia and dramatic influxes of refugees into southern Mesopotamia around 2170 BCE.

The nomadic Amorites, called Martu by the Sumerians, invade from the northwest.

Mountain tribesmen called the Gutians, who are possibly Caucasian-speakers, infiltrate Akkad from the region between the Tigris and the Zagros Mountains to the east, though these people probably also live on the middle Euphrates during the third millennium.