Complex sentence: Established in 925, it ruled as a sovereign state for 150 years; its participation was marked in various conflicts with the Venetians, Bulgarians, Magyars and, occasionally in an opposition against the Pope.
Split into simpler sentences: Established in 925, it ruled as a sovereign state for 150 years. Its participation was marked in various conflicts with the Venetians, Bulgarians, Magyars and, occasionally in an opposition against the Pope.