Mircea the Elder (Romanian: Mircea cel Btrn, pronounced [mirtea tel btrn] (listen); c. 1355 31 January 1418) was the Voivode of Wallachia from 1386 until his death in 1418. He was the son of Radu I of Wallachia and brother of Dan I of Wallachia, after whose death he inherited the throne.

During the reign of Mircea the Elder, Wallachia controlled the largest area in its history, gaining Dobruja in 1388, the Banate of Severin in 1388/9 and Podunavia (which is suspected to be the Timok Valley). In addition, he was also granted the fiefdoms of Amla (Omls) and Fgra (Fugurash) in Transylvania.

The byname "elder" was given to him after his death in order to distinguish him from his grandson Mircea II ("Mircea the Younger"), although some historians believe the epithet was given to him as a sign of respect by later generations. He is considered the most important Wallachian ruler during the Middle Ages and one of the great rulers of his era, and starting in the 19th century Romanian historiography has also referred to him as Mircea the Great (Mircea cel Mare).

The Ottoman Interregnum, or the Ottoman Civil War (20 July 1402 – 5 July 1413; Turkish: Fetret Devri, lit. 'Interregnum Period'), was a civil war in the Ottoman Empire between the sons of Sultan Bayezid I following the defeat of their father at the Battle of Ankara on 20 July 1402. Although Mehmed Çelebi was confirmed as sultan by Timur, his brothers İsa Çelebi, Musa Çelebi, Süleyman Çelebi, and later, Mustafa Çelebi, refused to recognize his authority, each claiming the throne for himself. Civil war was the result. The Interregnum lasted a little under 11 years, until the Battle of Çamurlu on 5 July 1413, when Mehmed Çelebi emerged as victor, crowned himself Sultan Mehmed I, and restored the empire.