Mesopotamia, the 'land between the rivers', is the name given by the Greek historian Polybius (second century BC) to the region enclosed between the Tigris and the Euphrates in southern Iraq (Fig. 4.1).
In the 400 miles between Baghdad and the Persian Gulf, the land drops only about 30 feet (9 metres). The great rivers run slowly, often changing their courses and depositing enormous quantities of fertile silt. It has been calculated that the Tigris and Euphrates remove three million tons of eroded material a day from the highlands of Iraq, and deposit it on the plains. The resulting sediments carpet the southern part of Iraq with fertile soil, which ranges in depth from 16 to 23 feet (5 to 7 metres).
Agriculture in ancient Mesopotamia faced two major problems. The first was flooding. Because of the dryness of the climate, the soil is very hard. When heavy rainfall in northern Iraq coincided with the melting of the snows in the Taurus and Zagros mountains, the rivers, penned in by the iron- hard ground, often broke their banks causing great destruction. The second problem is that of salt in the soil--salinization. The water of both the rivers is slightly salty, and salt is also pushed upwards by the ground water. The rainfall is very low, and irrigation is difficult,so that the salt simply builds up, finally rendering the soil infertile. It is a hard land.
As in Egypt and Europe, the transition from the hunting and gathering form of life to a more settled agricultural existence seems to have occurred sometime between 10 000-5000 BC. An agricultural village, excavated at Jarmo in northern Iraq, has been shown by radiocarbon dating to have been inhabited between 5100-4500 BC.
By about 4000 BC the northerners had moved south into the fertile plains of the great rivers, and set up cities. They called their land Shumer (Shinar, Genesis 11:2) (Fig. 4.1). We know them as the Sumerians.
At the dawn of Sumerian history, we see a group of city states each with its own priest-king and its own divine protector. Ur was the city of Nanna the moon-god, and his wife Ningal. Erech belonged to Anu and Inanna, Nippur to Enil and Nin-lil, and Lagash to Ningursu and Baba.
The original Ur (Ur I) was the legendary birthplace of Abraham, father of the Arab and Jewish nations. It was supposedly destroyed in a catastrophic flood, which may be the flood described in the Bible.