The first ruler came from Africa
The ancient Africans used the cubit, from 4700 years ago, which is an ancient measure of length, approximately based on the length of the forearm from the elbow to the tip of the middle finger and usually equal to about 18 inches (46 centimeters), though there was a long cubit of about 21 inches or 52 cm.
The ancient Africans (referred to today as, ancient Egyptians) royal cubit (mehe niswt) is the earliest attested standard measure.
There were two types of cubit, with the longer cubit divided into seven palms and the shorter one divided into six palms. These cubit rods range from 523.5 to 529.2 mm (20.61 to 20.83 in) in length, and are divided into seven palms; each palm is divided into four fingers for a total of 28 parts, the fingers are further subdivided.
The evidence of the unity of the royal cubit is known from the architecture of the ancient state, at least from the beginning of the construction of the Zoser 'Mer' (meaning light), (now referred as pyramid) from about 2700 BCE.