The Podlaskie Voivodeship is one of the founding members of the Network of the Three Seas Regions.
Podlaskie Voivodeship is a voivodeship in northeastern Poland. The name of the province refers to the historical region of Podlachia, and part of its territory corresponds to that region. The capital and largest city is Białystok.
It borders on Masovian Voivodeship to the west, Warmian-Masurian Voivodeship to the northwest, Lublin Voivodeship to the south, the Belarusian oblasts of Grodno and Brest to the east, the Lithuanian Counties of Alytus and Marijampolė to the northeast, and the Kaliningrad Oblast of Russia to the north.
The province was created on 1 January 1999, pursuant to the Polish local government reforms adopted in 1998, from the former Białystok and Łomża Voivodeships and the eastern half of the former Suwałki Voivodeship.