In the movie The Golden Compass or the book Northern Lights, they are called Savalbjorn, not polar bears. There are only two they tell us the names of:

Iorek Byrnison (the one that is loyal to Lyra)

Iofur Raknison (the one that took over when Iorek was banished)

Iorek Byrnison's name is pronounced 'YOR-ek BUR-nis-on'

Iorek Byrnison is in the town of Trollesund in the book "The Golden Compass" by Philip Pullman. He is initially found imprisoned in a mining village near Trollesund, before being rescued by Lyra.

lyra silvertongue, will parry, marisa coulter, iorek byrnison, lee scoresby, and a lot of other persons. read is again if you did not understand it

Iorek Byrnison was exiled from the armored bears because he killed another bear in a fight over leadership, breaking their customs. He was then tricked out of his rightful armor and forced into exile by the current bear king, Ragnar Sturlusson.