Wikipedia
The Karasids or Karasid dynasty ( Ottoman قرا صي; Modern Turkish Karesioğulları, Karesioğulları Beyliği), also known as the Principality of Karasi and Beylik of Karasi (Karasi Beyliği or Karesi Beyliği ), was an Anatolian beylik in the area of classical Mysia (modern Balıkesir and Çanakkale provinces) from ca. 1297-1360. It was centered in Balıkesir and Bergama, and was one of the frontier principalities established by Oghuz Turks after the decline of the Seljuk Sultanate of Rum.
They became a naval power in the Aegean and the Dardanelles.
They were the first beylik to be taken over by the neighboring Osmanoglu dynasty, who were later to found the Ottoman Empire. The acquisition of Karasi allowed the Ottomans to begin the conquest of European lands in Rumelia across the Dardanelles.
The province (sanjak, later vilayet) of Balıkesir was called the sub-province (sanjak, later vilayet) of Karasi until the early years of the Republic of Turkey, after which it was renamed after its central town Balıkesir.