The Wadai Sultanate (Arabic:Saltanat Waday, French: royaume du Ouaddaï, Fur: Burgu or Birgu; 1501–1912) was an African sultanate located to the east of Lake Chad in present-day Chad and the Central African Republic. It emerged in the seventeenth century under the leadership of the first sultan, Abd al-Karim, who overthrew the ruling Tunjur people of the area. It occupied land previously held by the Sultanate of Darfur (in present-day Sudan) to the northeast of the Kingdom of Baguirmi.

Prior to the 1630s, Wadai, also known as Burgu to the people of Darfur, was a pre-Islamic Tunjur kingdom, established around 1501. The Arab migrants to the area which became Wadai claimed to be descendants of the Abbasid Caliphs, specifically from Salih ibn Abdallah ibn Abbas. Yame, an Abbasid leader, settled with Arab migrants in Debba, near the future capital of Ouara (Wara).

In 1635, the Maba and other small groups in the region rallied to the Islamic banner of Abd al-Karim Al Abbasi, who was descended from an Abbasid noble family, led an invasion from the east and overthrew the ruling Tunjur group, who at the time was led by a king named Daud. Abd al-Karim was the son of Yame the Abbasid. Abd al-Karim secured and centralized his power in the area by marrying the Tunjur King Daud's daughter, Meiram Aisa, and then forming other marriage pacts with local dynasties and tribes, such as the Mahamid and Beni Halba tribes. Abd al-Karim became the first Kolak (Sultan) of a dynasty that lasted until the arrival of the French.

Read more: https://en.wikipedia.org/wiki/Wadai_Empire