The downfall of the Serbian Empire during the third quarter of the 14th century caused a change in the rule of Zeta. Feudal noblemen from the Balsic family rose to power. Three brothers: Djuradj I, Stracimir and Balsa II came suddenly onto the historical stage and they started to create their own territory out of nothing in the area of Shkoder, and then they expanded their rule over the towns and lands all the way to Kotor. The history of this feudal family is closely connected to the history of Bar, since they ruled over it until 1405, and then from 1412 to 1421.
The first generation quickly faded away (from 1372 to 1385), however, managing to obtain great possessions, even to rule over Durres, which Balsa II ruled over with the title "Duke of Durres". However, this was the first time that the rulers of Zeta came into contact with the Ottomans who tortured the people and attacked the lands of the Balsic family. In 1385, Balsa II  was killed in a battle with the Ottomans in the Saursko Polje near Berat.
War quickly broke out between the "rulers of Zeta", Djurdje II and Radic Crnojevic. In this war Ratac, which was then under the jurisdiction of Bar, was destroyed. In 1391, during negotiations, Djuradj II was imprisoned by the Ottomans who released him after he had handed over Skadar Drivast to them, and the economically important Sveti Srdj. This is how the Ottomans came into direct contact with the town district of Bar.
Djuradj II died in 1403, and he did not care who succeeded him: "my son or my relative or someone from a different tribe, whatever the Lord commands..." His heir was actually his son Balsa III from his marriage with Jelena, the daughter of Prince Lazar Hrebeljanovic. During this period the town became the royal capital of the Balsic dynasty.
In 1405 a war started between Venice and the Balsic family, and it showed that the towns were unhappy with the Balsic rule, and with no great effort, Marin Caravello, the commander of the Venetian fleet, managed to take Bar, Ulcinj and Budva. Balsa had been at war with Venice for 8 years, and in 1412, he managed to lay siege to Bar and reclaimed it, and later, after the war, placed his court in Bar.
After Balsa III Balsic's death, the town went to the Serbian rulers, as part of their heritage - firstly Stefan Lazarevic, and then Djuradj Brankovic. After he arrived with his army in 1421, Stefan Lazarevic conquered the Upper Zeta, Drivast and the surrounding area of the town. Despot Stefan did not stay long in Zeta. In November 1421 he gave control over Bar to Duke Mazareko, who was in the town as regent and who was accepted as the Serbian ruler in St. George's Church  by the noblemen. Mazarek stayed on as the despot's comissioner. The despot recognized the right of Bar's nobility to manage the town and have their own judicial system, and according to the tradition, it was supposed that he handed over the entire governing power to the patricians and that during his rule the seniores (magnates) grew to become nobiles (nobles).
Stefan was succeded by the despot Djuradj Brankovic, who spent nine whole months in 1440/1441 in Bar planing unsuccessfully to renew the Serbian state, which was lost for many centuries after the fall of Smederevo in 1439. Thanks to the fact that it served as the seat of power for the duke - during the time of Djurad Brankovic's duke Altomano - Bar was the capital of Zeta for 20 Years under the rule of the despot (1421 - 1441).
In 1442, the town was for a while under the rule of Stefan Vukcic Kosaca.