Who founded the first major empire in 13th century BC ?
It has been estimated that the Maurya Dynasty controlled an unprecedented one - third of the world 's entire economy , was home to one - third of the world 's population at the time ( an estimated 50 million out of 150 million humans ) , contained the world 's largest city of the time ( Pataliputra , estimated to be larger than Rome under Emperor Trajan ) and according to Megasthenes , the empire wielded a military of 600,000 infantry , 30,000 cavalry , and 9,000 war elephants .