People need to comunicate in the distance, and their efforts to write, have began with usage of figures called hieroglyphs. Therefore, in order to write, people needed to draw a numer of hieroglyphs, which then were read based on the representative letters. Nevertheless, this writing method wasn't practical and it took a lot of time... They thought of simplifying different figures, by stylizing them in the maximum, and thus I think the letters were borne. Inventing letters was a slow process, a kind of long evolution, wich was a continuation of symbols comming to light, a process started long before. The studies show that initial writings are those of Sumerians and they date back to 4000 B.C. followed by Egyptian hieroglyphs dating back to 3200 B.C, and later on Phoenician alphabet in 1050 B.C.