What is Cuneiform?
Cuneiform was the writing system of the Ancient Mesopotamians. It was used for two different languages, Sumerian and Akkadian. For most of the time cuneiform was in use, Sumerian was to them as Latin is to us; it was a dead language that they taught in schools, but was not the language the people used in their daily lives. That was Akkadian, and over time Sumerian died out completely in favor of Akkadian. But as the language Aramaic became more popular in that part of the world, Mesopotamia also began to adopt it, and the clay tablets became less and less common (Aramaic is written on parchment with pen and ink). The most recent cuneiform tablet found was from about 80 C.E.
There are three different types of cuneiform script: Old Persian, Elamite, and Babylonian. After many years of work, a small understanding of Old Persian surfaced. But the big breakthrough was when an inscription of King Darius cut into the Zagras Mountains in western Iraq near Behistun was discovered. It was written in all three scripts in different places, and once it was copied was of great use in deciphering cuneiform. But it enormous, and just copying it was a difficult job. Sir Henry Creswicke Rawlinson of Britain took on the challenge, and later deciphered cuneiform completely. Unfortunately, he never wrote down how he figured it out, causing problems for future scholars.
In 689 B.C.E., King Sennacherib sacked Babylon and then declared that the city must be left deserted and destroyed for 70 years, by decree of the god Marduk. Then his son Esarhaddon took over the throne in 680 B.C.E., and claimed that Marduk had reversed the number, so they could restore Babylon after only 11 years. Now this story is only possible because the entire writing system consists of 5 wedge-like symbols that are used to create all 600+ characters. This is unique compared to many modern languages; their formation is such that an incident like the one in this story is not possible.
The main purpose of cuneiform was prosaic, meaning that it was only used for practical purposes such as record-keeping, legal texts, medical texts, and religious purposes. The only literary texts they had were what the children copied in school in order to learn how to write. An example of this is the famous Epic of Gilgamesh.
Cuneiform dates back to about the same time period as Egyptian hieroglyphs. It originally was thought to have predated hieroglyphs and started the creation of writing systems in various countries, but recent discoveries have debunked that theory, as older hieroglyphic texts have emerged dating back to the time of very early cuneiform texts.