The First Bulgarian Empire
The First Bulgarian Empire came to an end when it connected to the Byzantine Empire after being in operation during the 7th and 11th centuries. The merger took place in 1185 AD and was led by Khan Asparukh. His leadership led the Bulgars from Central Asia as they were a pagan tribe.
While they were being exiled, they conquered and captured the Province of Moesia, but when the Christian religion grew in Europe, it became too much for them to handle.
The Sumer Empire
Sumer, during its popular days, was the largest city in the world and registered in Iraq. The Mesopotamian empire was versed in its development of the agriculture sector. Records have it that they were the first to conduct draining marshes to use as farmlands and were instrumental in the trading and industries sectors. The empire began in 5400 BC and had an estimated population of close to 60,000.
They also established a script known as Cuneiform, which is a major accomplishment for the empire.