Bielsko-Biała (; , , ) is a city in southern Poland, with a population of approximately 168,319 as of December 2021, making it the 22nd largest city in Poland, and an area of . It is a centre of the Bielsko Urban Agglomeration with 325,000 inhabitants and is an administrative, automotive, education, transport, and tourism hub of Podbeskiedzie Region as well as the Bielsko Industrial Region. It serves as the seat of the Bielsko County, Euroregion Beskydy, Roman Catholic Diocese of Bielsko–Żywiec and the Evangelical Church Diocese of Cieszyn. Situated north of the Beskid Mountains, Bielsko-Biała is composed of two former towns which merged in 1951 – Bielsko in the west and Biała in the east – on opposite banks of the Biała River that once divided Silesia and Lesser Poland. Between 1975 and 1998, the city was the seat of Bielsko Voivodeship and currently lies within the Silesian Voivodeship. The city is currently subdivided into 12 districts and is a member of the Association of Polish Cities (Związek Miast Polskich). History Both city names, Bielsko and Biała refer to the Biała River, with etymology stemming from either biel or biała, which means "white" in Polish. Bielsko The remnants of a fortified settlement in what is now the Stare Bielsko (Old Bielsko) district of the city were discovered between 1933 and 1938 by a Polish archaeological team. The settlement was dated to the 12th – 14th centuries. Its dwellers manufactured iron from ore and specialized in smithery. The current centre of the town was probably developed as early as the first half of the 13th century. At that time a castle (which still survives today) was built on a hill. In the second half of the 13th century, the Piast dukes of Opole invited German settlers to colonize the Silesian Foothills. As the dukes then also ruled over the Lesser Poland lands east of the Biała River, settlements arose on both banks like Bielitz (now Stare Bielsko), Nickelsdorf (Mikuszowice Śląskie), Kamitz (Kamienica), Batzdorf (Komorowice Śląskie) and Kurzwald in the west as well as Kunzendorf (Lipnik), Alzen (Hałcnów) and Wilmesau (Wilamowice) in the east. Nearby settlements in the mountains were Lobnitz (Wapienica) and Bistrai (Bystra). After the partition of the Duchy of Opole in 1281, Bielsko passed to the Dukes of Cieszyn within fragmented Poland. The town was first documented in 1312 when Duke Mieszko I of Cieszyn granted a town