Writing, at least in its most primitive form, has been around for at least 5000 years, first in Mesopotamia (modern day Iraq) where cuneiform was used between 3400 and 3300 BC. It is now believed that full writing systems appear to have been invented independently at least four times in human history and over a relatively short period of time of 400 years.
Early pictorial signs were gradually substituted by a more complex system of characters representing the sounds of Sumerian, the language of Sumer in Southern Mesopotamia. Beginning in 2900 BC these began to be impressed in wet clay with a reed stylus, making wedge-shaped marks which are now known as cuneiform.
The process of writing cuneiform stabilized over the next 600 years. Soon curves were eliminated, signs simplified and the direct connection between the look of pictograms and their original object of reference was lost.
Sometime during this period, the symbols-which were initially read from top to bottom-came to be read from left to right in horizontal lines.
With the invention of writing, soon came the invention of ink, pens and brushes, but that is for another time.