The Sumerians were the first known people to settle in Mesopotamia over 7,000 years ago, between the Tigris and Euphrates rivers (modern day Iraq). Sumer was often called the cradle of civilization. By the 4th millennium BC, it had established an advanced system writing, spectacular arts and architecture, astronomy and mathematics. The origin of the Sumerians remains a mystery till this day.
Greek Alphabet Greek civilization laid the foundation for many of the accomplishments of the western world. the Greeks took the Phoenician or North Semitic alphabet and changed five consonants to vowels. Greeks applied geometric structure and order to the uneven Phoenician characters, converting them into art forms of great harmony and beauty. greeks developed Boustrophedon writing method-for every other line reads in the opposite direction.
Indus culture seems to have gradually spread from west to east, with sites towards central and southern India flourishing after Harappa and Mohenjo Daro had declined. The drying up of the ancient Saraswati or Ghaggar-Hakra River, east of and parallel to the Indus, may also have affected the civilization. There are numerous Indus sites along that river bed.