The name Plaški was first mentioned in 1163 in documents of the Split diocese of the Roman Catholic Church. The second mention dates from 1185 and relates to the establishment of new Krbava diocese, which the parish of Plaški became a part of. Plaški county ("Comitatus Plazy") was a separate administrative region until 1193, when it became part of Modruš county and came to be owned by the Frankopan family. In the name of Frankopans Plaški was governed by the Zebić family of nobles, who were their loyal vassals (even today a part of Plaški is called Zebići).