Svetoslav Suronja

After the death of their father, his brothers Krešimir III and Gojslav started organizing a rebellion against him since Svetoslav rejected sharing power over the kingdom. The brothers had asked Bulgarian emperor Samuil for aid, even though the emperor was at war with the Byzantine Empire. In the war, the Byzantines were supported by Venice and Svetoslav Suronja, who had continued his father's policy. Samuil had accepted the revolters' invitation and attacked Croatia in 998, which started the last of three Croatian-Bulgarian wars. In his rampage, he took all of Croatian Dalmatia up to Zadar after which he ended his rampage, returning home to Bulgaria through Bosnia. Samuil gave all the territory he took to the revolters Krešimir and Gojslav. Using this newly gained territory and further Bulgarian aid, the brothers overthrew their elder brother, Svetoslav Suronja, and became rulers of Croatia.

Svetoslav's reign was particularly unpleasant for the Dalmatian cities, as they were occasionally raided and pillaged by his supporters. The cities asked the Venetian Republic for help in autumn of 999, which encouraged Venice to make a pact with the Byzantine Empire in order to secure the cities for themselves.[2] Using events like the casus belli, the Venetian Doge Pietro II Orseolo launched a campaign in Dalmatia against Croatia in 1000. During May, Croatia lost the islands Cres, Lošinj, Krk and Rab to the Doge, who was eventually received in Zadar and recognised as its master. Svetoslav sent envoys to the city offering peace, but the Doge declined and decided to further his campaign. From here the island Pašman was taken and, with negotiations, the city of Biograd.

He was the father of Stephen I of Croatia, and Stjepan Svetoslavić.[3] His grandson, Dmitar Zvonimir, later became the Croatian king in 1074.