The ancient region of Mesopotamia Kay between what two major rivers?

Mesopotamia is the land between Rivers Euphrates and Tigris.

Explanation:

Mesopatamia is home to the one of the earliest and the most advanced civilizations in human history. Today, these lands belong mainly to Iraq, Kuwait, South Eastern Turkey, Iran and Eastern Syria.

Many wealthy and notable cities emerged during the 1st millennia in this region. Some of them are,

Washukanni, Nineveh, Hatra, Assur, Nuzi, Palmyra, Mari, Sippar, Babylon, Kish

Out of these, the most notable and the most powerful cities were Babylon and Palmyra.

Moreover, state like Summer, Assyria, Babylonia and Akkadian empire were highly advanced and influential!