People settled in Egypt as early as 6000 B.C. Over time, small villages joined together to become states until two kingdoms emerged: Lower Egypt, which covers the Nile River Delta up to the Mediterranean Sea in the north, and Upper Egypt, which covers the Nile Valley in the south. (The Nile River flows from south to north, so for the ancient Egyptians, the southern part of the country was "up.") Around 3100 B.C., a king (later called a pharaoh) united these two lands to be one country, and so historians begin the long history of ancient Egypt here, dividing it into different periods.