Nicaea (now İznik) dates back to 4th century BC. First Council of Nicaea (325 AD) condemned Arianism. Council established Nicene Creed and defined church-state relations
Founded in 1362 by Orhan Bey as Pazarköy. Became district center in 1879, then Bursa province in 1893. Greek occupation lasted 1920-1922, ending in 1922