As the oldest son of Stephen II of the Šubić noble family, he inherited the title of count of Bribir.

The contest over the lands of the Kačić family in southern Croatia, who were known for piracy in the Adriatic Sea, brought Paul into conflict with the Republic of Venice.

During the succession crisis of the 1290s, Paul emerged as one of the most powerful oligarchs in the realm, and was the main ally of the Angevins in their struggle against the Árpád dynasty.

The rebellion was quickly quelled, and Paul passed the title of Bosnian ban to his son, Mladen II.

The king's authority over the lands held by Paul was only nominal throughout the entirety of his rule, during which he managed to turn his titles into hereditary ones for his family.

He issued his own coin, minted with silver from Bosnia, and arranged the establishment of three new Catholic dioceses in Croatia.

[5][6] Paul's father, Stephen II, was involved in the war with the Mongol Empire in 1242, when King Béla IV took refugee in the city of Trogir, which he governed.

[21] The lands owned by the Šubićs did not form a compact area, and they competed with other noble families for control over counties and forts.

[22] Paul sought to consolidate his control over the holdings of the Kačić family, a pirate stronghold in southern Croatia, centred around the city of Omiš.

[23] The Angevins controlled southern Italy, which was an important source of grain for Dalmatian coastal cities and the hinterland in late 13th century.

Paul's representatives in the negotiations guaranteed that the pirates from Omiš would not attack Venetian ships and that they would not sail in the northern Adriatic.

The Venetians guaranteed that they would not attack Paul's territories and gave his brother, George I, a free passage in his visits to the Papal States and in other trips.

[25] Paul turned to seeking allies in Venice, through his ties with the Tiepolo family,[26] as well as in the Venetian-controlled Dalmatian communes of Rab and Zadar.

[28] He shared common interests with the Roman Curia in suppressing heresy in the region and countering Venetian dominance in the Adriatic, and both supported the House of Anjou in their claim to the throne.

Prior to becoming pope, Nicholas was the Franciscan minister provincial of Slavonia, which covered the Kingdom of Croatia and Dalmatia.

[31] The Angevins primarily turned to Paul, while Andrew found an ally in Slavonian Ban Stephen III Babonić.

[34] In 1292, Charles Martel's father, Charles II, in the name of his son, awarded Paul and the Šubić family the hereditary rights to all of Croatia from the Gvozd Mountain to the Neretva River,[30] "with all the barons, vassals, cities, castles, and villages, with adjacent islands and all the rights and appurtenances", except for the westernmost part of Croatia, ruled by the Frankopans.

[34] In 1293, Andrew III made a similar gesture by naming Paul the hereditary ban of Croatia and Dalmatia.

[35] Andrew III also asked Paul to recognize his mother, Tomasina Morosini, as the duchess of all Slavonia, a title that covered the entire territory from the Drava and Danube rivers to the Adriatic sea.

[35] The same year, Charles II confirmed all possessions of Paul and his brothers, both current and any in the future, on the condition that the Šubićs provide troops for the Angevin campaigns.

[44] Paul was not involved in Charles Robert's subsequent activities in Hungary, and focused on expanding his realm to the city of Zadar, then under Venetian rule, and the Banate of Bosnia.

[47][45] George, who ruled as count of maritime towns,[10] maintained stronger contacts with the Angevins due to the threat of Venice.

The main ally of Paul in Bosnia was Hrvatin Stjepanić of the Hrvatinić family, with kinship ties to the Šubićs, who ruled as Count of Donji Kraji.

The offensive was over in June, when Mladen I, as the new ban of Bosnia, issued trading privileges to Split from Foča, a town on the banks of the Drina.

[52] The death of his brother Mladen I in June 1304, who had been reportedly murdered by the supporters of Stephen I Kotromanić, described by the Šubićs as heretics, compelled Paul to lead an army into Bosnia and reaffirm his authority.

[56] A Franciscan monastery of Saint Elizabeth, where his sister Stanislava served as part of the Poor Clares order, was also built in Skradin.

[57] The Šubićs invoked the memory of earlier Croatian dukes and kings of the Domagojević and Trpimirović dynasties, in order to portray their rule as a continuity.

[61] Stone inscriptions mentioning the 9th century Duke Branimir were restored and placed in newly constructed church buildings.

Both Pope Clement V and King Charles Robert protested the attacks on Zadar, and Venice agreed on peace negotiations that began in April 1312.

[60] After his father's death, Mladen kept to himself the title of ban of Bosnia and lord of Hum, and only let his brother George II, the second son of Paul, to participate in the higher level of government.