Domagoj, also known as Domagoi in Latin, ruled as the Duke of Croatia from 864 to 876, establishing the Domagojević dynasty. He seized the Croatian throne following Trpimir I's death, ousting his sons from power. Unlike his predecessors, Domagoj actively engaged in Adriatic affairs, advocating force and participating in numerous conflicts, notably against the Arabs, Venice, and East Francia. His aggressive tactics and support for piracy strained relations with Pope John VIII, further deteriorating when Domagoj showed no leniency to his conspirators. Though formally a Frankish vassal, he exploited the Frankish succession crisis to stage a successful rebellion against Carloman of Bavaria. Upon Domagoj's death in 876, his son ascended but was later deposed and expelled by Zdeslav in 878, marking a shift in Croatian leadership.

Domagoj of Croatia - Wikipedia