- Yıldırım Bayezid I, become Sultan of Ottoman State.
- Ottomans attacked Kastamonu in 1391 and Ottomans won.
- Ottomans attacked Balkans in 1392, 1393, 1394, 1395, 1397 and Ottomans won.
- Ottomans enveloped Konstantinapolis in 1396 during Crusaders attacked Niğbolu and Ottomans came to Niğbolu. Ottomans won.
- Timurid dynasty attacked Ankara in 1402. Ottomans were defeated by Timurid dynasty. Yıldırım Bayezit was taken captured. Civil war started in Ottoman State, 1402. A lot of counties became free. Civil war finished in 1413. Yıldırım Bayezid's son, Mehmet I became Sultan of Ottoman State. He killed other brothers.
- Ottomans fought Wenedyk in 1416. Ottomans were defeated by Wenedyk. But, Wenedyk didn't capture any castle and city. Mehmed I, attacked Anatolia and won. So, Ottomans captured a lot of Turk Beylics. Mehmed I died in 1421. His son Murat II became Sultan of Ottoman State.
- Always Crusaders attacked Balkans. And Ottomans were defeated by Crusaders and signed up Edirne-Segedin Treaty in 1444. So, Danube became border Ottomans with Hungarian. Also, Murat II abondoned his throne in 1444. His son Mehmed II became Sultan of Ottoman State. But, Hungarians attacked Balkans in same year.
- Murat II came back to Sultanate. Hungarians were defaeted by Ottomans. But, Crusaders attacked Kosovo in 1448. Ottomans won. After this war, European retreated and Ottomans rinsed in Balkans and Anatolia. Murat II died and Mehmed II became Sultan of Ottoman Empire in 1451. And, after all these Mehmed II would have opened a new age.
Note:Some errors on en. wikipedia about Ottoman Empire pages.