Two of history's greatest conquerors could never have met, born some fifteen centuries apart. Alexander the Great destroyed the Persian Empire before he was thirty1; Genghis Khan forged the empire that would become the largest contiguous land empire the world has ever seen. So who conquered more, and who was the greater commander? Here they are, side by side.
Uniting the steppe and conquering much of northern China
Gaugamela, 331 BC
At its height
The largest contiguous land empire in history (with his heirs)
From Greece to the edge of India
Battle record
Rarely beaten in a lifetime of conquest
Never lost a major battle
Undoing
Died on campaign in 1227; the empire split among his heirs
Died at 32; his empire split among his generals
Lasting legacy
Reshaped Eurasia, its trade and its peoples
The Hellenistic age and the model of the conqueror
Genghis Khan: the empire from the steppe
Genghis Khan united the warring tribes of Mongolia and turned them into the most formidable army of the age, mobile, disciplined and merciless. He conquered much of northern China and Central Asia, and by the time he died in 12273 his empire already stretched across Asia. Under his sons and grandsons it grew into the largest contiguous land empire in history4, reaching from the Pacific toward the gates of Europe.
Genghis Khan in a 14th century portrait from an album of Yuan emperors, painted on silk after his death. National Palace Museum, Taipei. Public domain
Alexander: the undefeated conqueror
Alexander the Great inherited a superb army from his father Philip1 and, in barely a decade, destroyed the Persian Empire and marched to India. His victory at Gaugamela in 331 BC is one of the most famous in history5, and he never lost a pitched battle2. He died at thirty-two with no settled succession1, and his empire was torn apart by his generals.
The Alexander Mosaic from Pompeii, a Roman floor mosaic after a Hellenistic painting, showing Alexander charging Darius III of Persia at Issus. Public domain
The verdict
By sheer size, Genghis Khan conquered more: the Mongol realm dwarfed Alexander's, though it reached its greatest extent under his heirs. Alexander conquered faster and younger, and never lost a battle in the field. One built an empire that reshaped a continent for generations; the other set the ancient world's benchmark for the perfect conqueror.
The empire of Alexander the Great, 336 to 323 BC, with his route of conquest from Macedonia to the Indus. Map from William R. Shepherd's Historical Atlas. Public domain
Each commander above has a full biography on this site, with its own sources. Judgements of who was "greater" are ours and openly a matter of debate; the facts and dates follow established histories. See our editorial approach.
Frequently asked questions
Who conquered more, Genghis Khan or Alexander the Great?
By area, Genghis Khan: the Mongol Empire became the largest contiguous land empire in history, far bigger than Alexander's, though it reached its peak under his successors. Alexander conquered his empire faster and much younger.
Did Genghis Khan ever lose a battle?
Rarely. He suffered setbacks early in his rise6 but was never decisively beaten once his empire was established, and he died undefeated on campaign.
Did Alexander the Great ever lose a battle?
He never lost a major pitched battle. His empire fell apart only after his early death at thirty-two, not through defeat in the field.
How big was the Mongol Empire?
At its height, under Genghis Khan's successors, it was the largest contiguous land empire in history, stretching from the Pacific toward eastern Europe.
Who was the greater general?
It is a genuine debate. Alexander has the flawless record and the daring of youth; Genghis Khan built a larger empire and an army that dominated for generations. They fought in different worlds with different tools.
Sources and notes
Numbered notes in the text point to the works below.
A. B. Bosworth, Conquest and Empire: The Reign of Alexander the Great (Cambridge University Press, 1988). ↩ abc
