Youngest Monarchs To Ascend The Throne

They missed a few

Alexander IV, Alexander the Great's only son, was also crowned in the womb, to rule with his uncle, the feeble Phillip III, Alexander IV was poisoned when he was 14

Basil II was five and his brother Constantine VIII was three when they became co-Emperors of the Byzantine Empire. Basil II survived the regencies and became one of the greatest Emperors. Constantine VIII survived the regencies and his brother to be a rotten Emperor. His reign is thought to be the beginning of the end for the Eastern Roman Empire.

Ivan VI was two month old when he was proclaimed Emperor of Russia. His regency was overthrown 13 months later and the poor soul spent his remaining 20 years in prison, seen by no one except his jailers, until he was ordered to be strangled by Catherine the Great.

Ivan the Terrible was only three when he became Tsar of all the Russias. He was mistreated so badly during his minority that it might have led to his bloody reign

The last Emperor of China, Puyi, was only two when he became Emperor

Henry VI was eight months old when his father, the Shakespearean hero Henry V died. His reign was a complete disaster. England lost its holding in France, England erupted into civil was and Henry became insane