The Byzantine Empire
It survived when Rome didn't. Why?
Because of their military, political leaders, The Byzantine Empire fell to the Ottoman Turks in 1453.
The Byzantine Empire was located around Greece and Asia Minor, inhabiting some parts of North Africa and the Middle East as well.
The Byzantine Empire is located around Greece and Asia Minor. It was established in 330 AD when the Western Roman empire was falling by Constantine in the capital city of Constantinople, an excellent point for trade. The empire reached out to the coast of North Africa, the Balkans, and the Middle East. It survived the fall of Rome but later fell to the Ottoman Turks in 1453.
The Byzantine Empire's military was among the most powerful military forces in Europe from the seventh to 12th centuries. The military itself was quite small, only 120,000 men at it's peak. However, they established a Thematic System to the military which was organized around territorial army units to keep the army widespread but still powerful and deadly. They created a liquid made of naphtha, pitch, sulfur, lithium, potassium, metallic sodium, calcium phosphide and a petroleum base. They called this "Greek Fire". It was used by the Navy, because it only ignited when touching seawater. The Navy was also a force to be reckoned with. The Byzantine Empire was mostly surrounded by water, so the Navy was strong as a result of that. The Empire was located in strategic spot between the Black Sea and Mediterranean Sea. This benefitted the trade as well as the Navy because they were right in the middle so they can protect themselves from an attack from either side of the Empire. When the Empire fell to the Ottoman Turks in 1453, the size of the army was very small: only 50,000 men. Compared to the Turks' 150,000 men , the Byzantine Empire didn't stand a chance even though they were one of the strongest armies in the world.
The first political leader of the Byzantine Empire was Constantine. He also founded the Empire and was an Eastern Orthodox Christian. He was able to make the religion spread throughout the empire by teaching the religion. However, there were some political leaders that were not as good of a leader. For example, John Cantacuzene allowed the Ottoman Turks to take over the Balkan Peninsula. Another example is Basilicus, who set parts of Constantinople on fire, similar to the Roman Emperor Nero.