The assumption of the title of Herzog by Stjepan Vukčić Kosača is still an insufficiently clarified issue in historiography. Historians do not agree on whether this title was granted to Stjepan Vukčić by some ruler or if he bestowed it upon himself. In October 1448, Radič Sipaković, an envoy of Stjepan Vukčić, visited Ragusa, and the Ragusan authorities extended their congratulations on the occasion of the new Herzog dignity for his suzerain Stjepan.

“Prima pars est de dando libertatem domino Rectori et suo paruo consilio respondendi Radiz Sipachouich ambaxiatori vayuode Stipani supra ambaxiata exposita et congratulandi de noua dignitate cherzech acquisita prout ipsi domino Rectori et consilio videbitur.” Pro ballotte omnes. 

 “Secunda pars est de ordinando hic.” 

“Prima pars est de donando suprascripto ambaxiator.” Per ballotte omnes. 

 “Secunda pars est de non.”

“Prima pars est de donando suprascripto ambaxiatori in illis rebus de quibus videbitur domino Rectori et minori consilio iperperis CC.” Per ballotte XVIIII, contra XV.

“Secunda pars est de donando ut supra iperperis CCXL.” (17.10.1448) Dubrovnik State Archives, Consilium Rogatorum vol. XI, f. 12v.