Why is it not easy to name the last Roman Emperor?

It is not easy to name the last Roman Emperor, because when the Roman Empire grew too big to be easily administered, it was divided into the Western Roman Empire and, eastern Roman Empire. However, some successors did not like this arrangement, and the Empire was reunited by different rulers over the next 100 years.

 The last ruler of the united Roman Empire was Theodosius I who was also known as Theodosius the Great. He died in 395 AD. The last Emperor of the Western Roman Empire was Romulus Augustus, who was forced to abdicate the throne in 476 AD. The Eastern Roman Empire lasted another 1000 years, but it became smaller and smaller, and was known as the Byzantine Empire. The last emperor of the East was Constantine XI Palaeologus, who was killed in 1453. However, Charles the Great, King of the Franks, revived the Holy Roman Empire in 800 AD, and the last Holy Roman Emperor was Francis II. He was overthrown in 1806 by Napoleon, who also abolished the Holy Roman Empire