The Zeta Banovina or Zeta Banate (Serbo-Croatian: Зетска бановина/Zetska banovina) was a province (banovina) of the Kingdom of Yugoslavia between 1929 and 1941. This province consisted of all of the present-day Montenegro as well as adjacent parts of Central Serbia, Kosovo, Croatia, and Bosnia and Herzegovina. It was named for the Zeta River which also gave its name to the medieval state of Zeta that roughly corresponded to modern Montenegro. The capital city of the Zeta Banovina was Cetinje.
Read more about Zeta Banovina: Borders, History, Demographics, Bans of Zeta