This is  true After that the Vladikas took over and then in  around  years later the Petrovi family takes over Also how is Zeta not the successor of the Kingdom of Duklja when it is Well during the time Duklja existed it was beginning to be called Zeta in the mids and generally why have been seing Zeta used a lot in the last few paragraphs in the history section in the Duklja article Well