Montenegro consisted of territories controlled by warlike clans. Most clans had a chieftain (''knez''), who was not permitted to assume the title unless he proved to be as worthy a leader as his predecessor. The great assembly of Montenegrin clans (''Zbor'') was held every year on 12 July in Cetinje, and any adult clansman could take part. In 1515, Montenegro became a theocracy led by the Metropolitanate of Montenegro and the Littoral, which flourished after the Petrović-Njegoš of Cetinje became the traditional prince-bishops (whose title was "Vladika of Montenegro").