Łomża is a city in north-eastern Poland, approximately 150 kilometres to the north-east of Warsaw and 80 kilometres west of Białystok. It is situated alongside the Narew river as part of the Podlaskie Voivodeship. It is the capital of Łomża County and has been the seat of the Roman Catholic Diocese of Łomża since 1925. Łomża is one of the principal economic, educational, and cultural centres of north-eastern Masovia as well as one of the three main cities of Podlaskie Voivodeship.