The Western Roman Empire fell to the Goths, Vandals and Huns who poured in from the east over a century - the Roman legions legions simply couldn't match them in numbers and the long frontier which they had to defend. Having allowed the Goths to settle inside the Danube line, hoping to use them to keep out the others, they had the enemy within the gates and by the late 5th Century CE the Western Empire had been taken over.
The Eastern Empire continued on, centred in Constaninople (now istanbul). Over the centures the territory was progressively eroded by intrusions from Asian invaders including the Seljuk Turks, and was even captured by a Crusade more interested in pillage than Christianity. With this weakened state the Ottoman Turks moved in and the territory shrank to just the environs of the capital. Isolated, it was finally beseiged and captured in 1453 CE by the Ottoman Turks under Mehmed II.
A Caliph.
It was Charles Martel, is the most famous defeat of Spanish Muslim invaders at Tours in 732.
Mohammed, the final Islamic prophet was Islam's first leader.
The Persian leader defeated by the Greeks was Darius.
The communist leader who defeated Hitler in the battle of stalingrad was Joseph Stalin. He was the leader of the USSR who defeated Germany in the battle of Stalingrad.
Saladin
A Caliph.
Francisco Pizarro defeated the Inca empire in 1535.
Napoleon bonaparte
Well, seeing as how this question is filled under Alexander the Great, I would assume that you should know that the leader of Macedonia, Alexander the Great, defeated the Persian empire and held the title and office of the king of Persians.
Mansa Muse
It was Charles Martel, is the most famous defeat of Spanish Muslim invaders at Tours in 732.
The Ottomans were led by the Sultan in political matter and the Caliph in religious matters.
Mohammed, the final Islamic prophet was Islam's first leader.
Sunni Ali Ber, a military leader, established the Sunni dynasty in the Songhai Empire in the late 15th century. He expanded the territory and power of the empire through military conquests and strategic alliances.
Well there have been few Muslim empires but Salah ad Din Yusuf ibn Ayyub (Saladin) was known for uniting the Muslims under one flag.
which empire? generally, a king who defeated other kings and absorbed their kingdoms into his own would be called an Emperor of an Empire. Be more specific for an exact name of an empire founder