Complex sentence: In 1975 Piła became the capital of the newly established Piła Voivodeship (province), which started a period of fast development of industry in the area as one of the most important cities of the region.
Split into simpler sentences: In 1975 Piła became the capital of the newly established Piła Voivodeship, which started a period of fast development of industry in the area. Currently Piła is one of the most important cities of the region.