Mehmed the Conqueror and the Ottoman Empire: how one sultan reshaped three continents

The Ottoman Empire began around 1299 when Osman, a Turkmen chieftain in Bithynia near the Sea of Marmara, founded a small principality in northwestern Anatolia, according to the World History Encyclopedia. Over the next two centuries his successors expanded that territory into an empire spanning parts of Europe, Asia and Africa.

Who was Mehmed the Conqueror?

Mehmed II was born on 30 March 1432 and first became sultan in 1444, at age 12, when his father Murad II briefly abdicated, according to the World History Encyclopedia. Murad II returned to the throne to handle military threats before his death in 1451, after which Mehmed II took sole and permanent control of the empire at age 19.

The siege that ended Byzantium

Mehmed II's forces besieged Constantinople, the capital of the Byzantine Empire, beginning on 2 April 1453, according to The Collector. The siege lasted roughly eight weeks before the city fell on 29 May 1453, when Mehmed II was 21 years old.

The Ottoman side fielded an estimated 60,000 to 80,000 troops, about 320 naval vessels and 69 cannons, per The Collector. Byzantine defenders numbered only about 6,000 to 7,000 trained soldiers, reinforced by roughly 30,000 to 35,000 conscripted civilians, with around 15 cannons of their own.

A key Ottoman weapon was a massive cannon known as the Basilic, built by the Hungarian engineer Orban. The Collector reports it measured about 7.3 meters in length, weighed more than 18 tons, and could fire 550-kilogram cannonballs up to 1.6 kilometers, though its slow reload speed limited it to roughly three to seven shots per day during the siege.

Byzantine emperor Constantine XI died defending the city when Ottoman forces breached its walls, bringing to an end more than a thousand years of Byzantine rule, according to The Collector.

Beyond Constantinople: campaigns, reforms and culture

Mehmed II's military campaigns did not stop in 1453. According to the World History Encyclopedia, he campaigned in Serbia between 1454 and 1459, conquered Greek territories including Attica, captured the Empire of Trebizond in 1461, fought Wallachian ruler Vlad III, and waged a prolonged war with Venice from 1463 to 1479 that extended Ottoman dominance in the Aegean.

At home, Mehmed II centralized Ottoman authority by weakening powerful noble families and introduced standardized secular law codes known as kanun, which governed taxation and administration alongside existing Islamic law, the World History Encyclopedia states.

He also rebuilt Constantinople's infrastructure, commissioning the Topkapi Palace, the Grand Bazaar and the Fatih (Conqueror's) Mosque, while patronizing poets, scholars and artists and collecting classical manuscripts. Mehmed II died during a military expedition in the spring of 1481, on 3 May, and was succeeded by his eldest son, Bayezid II.

How the empire was governed

Later sultans built on Mehmed II's centralizing reforms with two systems that defined Ottoman rule for centuries. The devshirme was a child levy, established under Murad I, that conscripted Balkan youths, converted them to Islam and trained the most capable among them as Janissary soldiers or administrators, according to the World History Encyclopedia. Separately, the millet system allowed non-Muslim religious communities a degree of self-governance over their own courts, schools and internal affairs.

The empire reached its greatest territorial extent in the 16th and 17th centuries, controlling land across Anatolia, the Balkans, mainland Greece, parts of the Arabian Peninsula, Egypt and the North African coast, the World History Encyclopedia reports.

How and when the empire ended

The Ottoman Empire went into decline after the late 16th century and, following defeat alongside the Central Powers in World War I, was formally dismantled in stages. Turkey's Grand National Assembly abolished the sultanate on 1 November 1922, and the last sultan, Mehmed VI, left Constantinople aboard the British ship HMS Malaya on 17 November 1922, according to Wikipedia's article on the abolition of the Ottoman sultanate.

The Treaty of Lausanne, signed on 24 July 1923, formalized international recognition of the new Turkish state, and the Republic of Turkey was proclaimed on 29 October 1923. The Ottoman caliphate, the dynasty's last remaining title, was abolished in March 1924 under Abdulmejid II, according to both Wikipedia and the World History Encyclopedia.