The Ottomans, known as Oghuz Turks at this time, attempt to claim land, starting with the unsuccessful conquest of Karacahisar under Osman I. Karacahisar is now a part of the Byzantine Empire and will go on to lie in Eskişehir Province of western Türkiye.
The Oghuz Turks return to Karacahisar once more, this time emerging triumphant. The Byzantines hand administration of Eskişehir over to them.
Osman I, descended from the Oğuz Turkmen and born in 1258 in Söğüt, northwestern Türkiye, officially founds the Ottoman Empire. He declares the Ottoman principality’s independence with the conquest of İnegöl, also in northwestern Türkiye. However, the nation known today as Türkiye will not be founded until the Empire falls.
Osman I attempts to gain territory from the declining Byzantine Empire in northern Bithynia, an ancient region in Türkiye. He ambushes the Byzantines at the plain of Bapheus, gaining the first major victory for the Ottomans.
Orhan I succeeds Osman I. The new ruler promptly captures Bursa in northwestern Türkiye from the Byzantines. Bursa now becomes the new Ottoman headquarters. Orhan I’s successor, Murad I, is born.
After a two-year-long blockade, the northern Byzantine city of Nicaea falls to the Ottoman Empire. After the 1329 Battle of Pelekanon, the Roman cities in Anatolia (the peninsula known today as Asia Minor) are surrounded. The city’s strong walls protect it from a direct attack, so the Ottomans starve the urban populations into surrendering. The Ottomans convert the Hagia Sophia in İznik in Nicaea from an Eastern Orthodox cathedral to a mosque.
Taking advantage of internal conflicts, Orhan I annexes the Karası region of northwestern Türkiye. The Ottomans reach the Sea of Marmara, which lies south of the Bosphorus Strait and northeast of the Aegean Sea.
An earthquake ravages the Gallipoli Peninsula. Many die and the city of Gallipoli crumbles. Süleyman Pasha capitalizes on the situation, leading the Ottomans into the fallen city. They take it for themselves, driving out the Greeks and advancing into Europe.
Aegean pirates kidnap Şehzade Halil, Orhan I’s son. The Ottomans pause their plans of European expansion, halting military operations while they secure his release. With Halil recovered, they set their sights on Adrianople, a key Byzantine city which lies in Türkiye bordering Greece.
Orhan I dies in Bursa after a 34-year reign. Sultan Murad I succeeds him and ascends the throne. His son, Yıldırım Bayezid, is born.
Murad I most likely begins the conquest of Rumelia, an ancient city northwest of Türkiye, by defeating the governor of Adrianople at the battle of Sazlıdere. The Byzantine governor flees, leaving the citizens to negotiate with the Ottomans. Adrianople falls, becoming the new Ottoman capital until 1453. The city’s strategic location makes it quite valuable, paving the Ottoman Empire’s way into the Byzantine capital of Constantinople.
Count Amadeus VI of Savoy leads a crusade to reclaim Byzantine land that the Ottomans conquered in 1354. Though ultimately unsuccessful, the count’s Christian forces briefly recapture Gallipoli, now in European Türkiye.
The Ottomans fight the Hungarian Crusader army. The Ottomans win a Pyrrhic victory, as Murad I dies in battle. His son, Bayezid I, succeeds him and becomes sultan. Bayezid I’s son, Mehmed Çelebi or Mehmed I, is born.
Many European states unite and establish a crusade against the Ottomans. The Ottomans defeat the Crusaders in battle at Niğbolu, a city located in modern-day northern Bulgaria. Bayezid I receives the title of sultan.
Bayezid I defeats and annexes the city of Karaman, located in the Central Anatolian region of Türkiye. He advances through Anatolia and occupies the remaining principalities. The Ottomans briefly occupy Anatolia.
Under the Devshirme system, non-Muslims in the Ottoman Empire must surrender their sons as a “tax.” Muslims then convert these enslaved Christian children to Islam and use them as slaves. Surprisingly, the system allows privileges for some slaves who train for work within the Ottoman government. Other slaves serve as Janissaries, elite infantry units that form the army’s core. Some grow powerful and wealthy, though this status is not hereditary.
The Timurid Empire, which rules Central Asia, Afghanistan and Iran, captures Bayezid I at the battle of Ankara near central Türkiye. He dies in captivity the next year. The relatively young Ottoman Empire faces a succession crisis when Bayezid I’s five sons, İsa Çelebi, Musa Çelebi, Süleyman Çelebi, Mustafa Çelebi and Mehmed I, fight for the throne. Civil war breaks out, beginning the Ottoman Interregnum.
After 11 years of civil war, Mehmed I defeats his last brother, Musa Çelebi, at the battle of Çamurlu near modern-day Samokov, Bulgaria. He crowns himself the Ottoman Empire’s next sultan, ending the Ottoman Interregnum.
Murad II succeeds Mehmed I. He reigns for the next 23 years until his son, Mehmed II, succeeds him — the young Mehmed II was previously deemed too immature to rule. Murad II takes over in 1446 until his death in 1451, when Mehmed II once again succeeds him.
The Ottomans reach the frontier of Constantinople and besiege it, forming a blockade by land and sea around the city. The capture effectively ends the Byzantine Empire. Mehmed II slaughters most of its people, which had already been ravaged by the Fourth Crusade and the Black Plague, and exiles many more. He renames the city Istanbul, or “the city of Islam.” Ottomans rebuild the Byzantine capital as the political and military capital of the Ottoman Empire, inviting exiled denizens back to maintain a population.
Sultan Mehmed II marches his troops into the Serbian capital of Belgrade, beginning the Ottoman–Hungarian Wars. The Hungarian army struggles as it runs out of available troops due to the Black Plague and poverty. They cannot afford the necessary equipment and must enlist peasants. Hungarian General János Hunyadi turns the tide for his troops, however, by skillfully dividing them to defeat the different groups of raiding Turks. The Ottomans desperately try to defeat Hunyadi.
The Ottoman raids begin regularly moving through Gallipoli into the province of Thrace, which constitutes modern-day southeastern Bulgaria, northeastern Greece and eastern Türkiye.
Mehmed II nominates his eldest son, Bayezid II, as the new sultan before he dies. Some Shi’a Muslims favor his younger brother, Cem, and revolt, but Janissaries quash the uprising. Bayezid II ascends the throne. Later that year, Cem declares his sultanate and takes power in Bursa, unsuccessfully proposing to split the Empire between his brother and him. Sultan Cem battles Sultan Bayezid II but loses and flees to Egypt. The two clash once more in Anatolia, and the defeated Cem seeks asylum in Rhodes.
A devastating earthquake hits Istanbul. It begins in the early morning, rapidly razing the entire city and affecting many other parts of the Empire. Thousands die and even more are injured. Homes, mosques and hospitals are demolished. Parts of the Hagia Sophia and the Topkapı Palace — the sultan’s main residence, administrative center and Janissary training facility — collapse. The Greeks send aid to the Ottomans.
Sultan Selim I (or Selim the Grim) succeeds Bayezid II. To decrease Persian influence within the Empire, he suppresses the Shi’a Muslims, who retreat to Persia (known today as Iran). Selim I frightens the Persian Safavid Empire into a non-aggression policy and conquers the Egyptian Mamluk Empire. Selim I widely expands fratricide, the murder of all the Sultan’s male relatives to prevent challengers to the throne.
The Ottoman army meets the Safavid army at Marj Dābiq, near the town of Dabiq, located in modern-day northern Syria. The Ottomans win an easy victory and induct Syria into the Empire. The next year, they defeat the Mamluk army and induct Egypt as well.
Süleyman I (or Süleyman the Magnificent) succeeds Selim I. He begins the Golden Age of Suleiman and unites the lands of Eastern Europe and the Eastern Mediterranean under his rule. The Ottoman Empire controls many Islamic holy lands, including Islam’s three holiest cities: Mecca, Medina and Jerusalem. Süleyman I becomes the earthly ruler of most Muslims. The Empire’s wealth, prosperity and stability attract many Muslim scholars to Istanbul.
Sultan Süleyman I invades Hungary. He defeats the Hungarian king at the Battle of Mohács in southern Hungary. The Ottoman Empire gains this new land.
Three years on, however, the Ottoman army will face defeat in Vienna, Austria, beginning the Empire’s slow and steady fall.
Credits
Researched by Kayra Altan
Produced by Khemraj Singh & Netleon Technologies Team
Revised by Atul Singh & Lee Thompson-Kolar
Reviewed by Nathaniel Handy & Ishtiaq Ahmed
Images courtesy of Creative Commons