A South Asian mountain range, stretching from Lake Van in southeastern Turkey, through the regions of Turkey, Iraq, and Iran collectively known as Kurdistan, and, continuing in Iran, forming the eastern boundary of the Mesopotamian Plain and the eastern shore of the Persian Gulf, finally ending at the Strait of Hormuz near Bandar Abbas.

The Zagros lie on the boundary between the Arabian Plate and the Eurasian Plate (or a subset of it sometimes identified as the Iran Plate).  Indeed they were formed as the Arabian plate push northwest into the Eurasian plate during the Miocene epoch between 40 million years ago and 18 million years ago, finally closing the Tethys Sea.

It is safe to say that the Zagros are more important to human history than even Mesopotamia just to the west:  This is where agriculture first developed1.  The wild varieties of grassy plants such as wheat, barley, oats, and flax, now staples of agriculture, are native to the region.  People stopped gathering wild wheat and started planting it in the valleys of the Zagros between 12,000 and 10,000 years ago, at the end of the last Ice Age.

When further climate change forced these people out of the mountains and down into Mesopotamia, requiring large-scale irrigation projects, and large-scale organization of manpower, civilization was born.

Throughout ancient times, various peoples thundered down out of the Zagros to plunder Mesopotamia: the Akkadians, Guti, Kassites, Mittani, Elamites, Assyrians, and finally the Medes and Persians.  The Assyrian capital, Nineveh (now Mosul), was in the western foothills of the Zagros, as was a major Elamite and Persian city, Susa, (now Shush). The Median capital, Ecbatana (now Hamadan), was on Zagros' eastern slopes, and the Persian capital, Persepolis, lies in a high valley in the southern Zagros.

The recent history of the Zagros has been a sad one: It was the principal theater of the bloody 1980-1989 Iran-Iraq War.

1Agriculture appears to have developed independently on the North China Plain, sub-Saharan Africa, and in North and South America, albeit later.