The two families: Barbo and Nicolich continued to live in Kozljak’s castle and the first floor was belonging to the Nicolich family and the second floor to the Barbo family. It is known also that in 1574, the successor of Nicolich family, Giuseppe Nicolich, was killed during a peasants revolt.

In 1620 Barbo family left Kozljak and moved to Belaj. It is known that also Barbo and Nicolich family added to their surnames the word Wachsenstein. The Nicolich family extinguished at the beginning of the 17th century and their substitute in Kozljak were families Diotalevi and Calotti, lords of few villages around Kozljak.

In end most of Kozljak’s properties remained to Castellano Barbo of Wachsenstein. He had three sons: Bernardino, Giorgio and Francesco. Bernardino was the lord of Paz, Giorgio was the lord of Belaj while Francesco remained in the Castle of Kozljak with Calotti family until 1630.

Giorgio moved away from Istria and Francesco did not have successors, so most of the Kozljak’s property became Bernardino’s successors properties. In 1668, Francesco Carlo Barbo sold Wachsenstein’s properties to Prince Auersperg, owner of the County of Pazin. This was the end of the Kozljak’s Castle importance.

The castle was restructured for the last time in 1400 and 1567. It has started to lose its strategic importance after the Austro-Venetian war at the beginning of the 17th century. Few decades later the administration of the Wachsenstein’s properties was transferred to the beautiful property in Belaj.