A number of Barbarian warlords led to the downfall of the Western Roman Empire, (the empire was split into east and west at the time) the Visigoths, the Huns, (although severely weakened after the death of Atilla) the Franks the Lombardi, the Vandals, the Ostrogoths, the Saxons and the Goths. Many more tribes were involved but these are the main ones.
The emperor
A brief definition of a Roman Emperor can be taken from the link below. "The Roman Emperor was the ruler of the Roman State during the imperial period (from about 27 BC onwards). The Romans had no single term for the office: Latin titles such as imperator (from which English Emperor derives), Augustus, Caesar and princeps were all associated with it. In practice, the Emperor was supreme ruler of Rome and supreme commander of the Roman legions."
The Roman Empire in the west ended in 476 AD, when the last Roman emperor, Romulus Augustus, was deposed by the Germanic king Odoacer. Odoacer then became the ruler of Italy and marked the end of the Western Roman Empire.
Augustus was not the ruler of a country. He was the ruler of an empire: the Roman Empire.
Depending on the time period, you would call a ruler in ancient Rome, a king, a counsul, a dictator, or an emperor. Remember that the Romans never used the term emperor for their ruler. They used the name Caesar, which became a title.
Odoacer was a Germanic chieftain who deposed the last Roman emperor, Romulus Augustulus in 476AD. This event ended the Western Roman Empire. Odoacer was the first Germanic ruler of Italy.
The emperor
Being emperor meant being in charge of the vast Roman Empire. The emperor was an absolute ruler.
Roman Emperor Nero
Odoacer was a barbarian chieftain who deposed the last Roman emperor in 476 AD, marking the end of the Western Roman Empire. He became the first King of Italy and ruled as a Germanic ruler. His reign marked the beginning of the Middle Ages in Europe.
A brief definition of a Roman Emperor can be taken from the link below. "The Roman Emperor was the ruler of the Roman State during the imperial period (from about 27 BC onwards). The Romans had no single term for the office: Latin titles such as imperator (from which English Emperor derives), Augustus, Caesar and princeps were all associated with it. In practice, the Emperor was supreme ruler of Rome and supreme commander of the Roman legions."
The Roman Empire in the west ended in 476 AD, when the last Roman emperor, Romulus Augustus, was deposed by the Germanic king Odoacer. Odoacer then became the ruler of Italy and marked the end of the Western Roman Empire.
Julius ceasar
The first Roman emperor named Constantine was Constantine I or the Great. He reigned a co-emperor from 306 to 324 and as the sole emperor from 324 to 337. He was the 57th Roman emperor.
napoleon Bonaparte crowned himself Emperor
Otto I the Great, Holy Roman Emperor (lived 912-973, reigned 936-973). The Holy Roman Emperor was ruler of the Holy Roman Empire, a predecessor of numerous countries mainly in central Europe.
Augustus was not the ruler of a country. He was the ruler of an empire: the Roman Empire.