This thesis studies life of Nikola Modruški and Marko Antun de Dominis. Nikola Modruški was born in 1427 and died in 1480. After successfully completing his studies in Italy, he became the Bishop of Senj, and subsequently of Modruš. His most significant role was that of papal legate, as a mediator at the court of Bosnian king, Stjepan Tomašević and Matija Korvin. He was also significant as he was present at the time of collapse of Kingdom of Bosnia. By the end of his life he lived in Italy. History remembers him as Humanist, promoter of Glagolitic script and through his literary work. Some of his most significant works are: De mortalium felicitate dialogus (eng. Dialogue on the Happiness of Mortals), De consolatione (eng. On Consolation), Navicula Petri (eng. Peter’s Barge), Oratio in funere reverendissimi domini d. Petri Cardinalis sancti Sixti habita a reverendo patre domino Nicolao episcopo Modrussiensi (eng. The funeral oration of Nicholas of Modruš for the cardinal priest Pietro Riario). Marko Antun de Dominis was born in 1560 and died in 1624. He was the Bishop of Senj and Archbishop of Split. He had a key role in finding the solution to the problem of question of Senj's Uskoks. He dedicated his life to the Unity of Church and to the primacy of the Pope and he criticized Catholic Church. He died in a dungeon of the Inquisition, and left his work which is considered to be his lifetime achievement, De republica ecclesiastica libri X (eng. Ecclesiastical republic). He was interested in Natural Sciences as well, and he wrote several works in that area De radiis visus et lucis in vitris perspectivis et iride (eng. Discussion Of the rays of sight and light lenses and long rainbow) and Euripus seu de fluxu et refluxu maris sententia (eng. Eurip or discussions on the inflow and re-flow of the sea).