Opole (; ; ; see below) is a city located in southern Poland on the Oder River and the historical capital of Upper Silesia. With a population of approximately 128,035 (December 2019), it is the capital of Opole Voivodeship (province) and the seat of Opole County. With its long history dating back to the 8th century, Opole is one of the oldest cities in today's Poland. It is also the smallest city in Poland to be the largest city in its province.