Ugrin Csák dominated the southern part of the Kingdom of Hungary, acquiring suzerainty over Upper Syrmia and other territories along the river Sava.
Historian Gyula Pauler simply called him the "powerful lord of Syrmia" in the late 19th century.
Bálint Hóman considered his influence extended to Trans-Drava, Syrmia and the Banate of Macsó.
According to Pál Engel and Attila Zsoldos, his dominion extended in the territory from Požega to Temesvár (present-day Timișoara, Romania), and ruled over the counties of Požega, Valkó, Bács, Syrmia, Torontál, Keve and possibly Temes and Krassó.
It is plausible that Ugrin dominated Syrmia County since the end of the 1270s as there were no records of any office-holders (ispáns) in the county since then.
Around the same time, Ugrin also extended his influence in the neighboring Valkó County, where he built his centre Újlak (Ilok).
Following his local rival Queen Tomasina's death, he acquired the whole county for himself.
In 1303, the curialis comes of Valkó County styled himself as the "official" of Ugrin Csák, which demonstrates his lordship in the region.
When Albertino Morosini left Hungary shortly after Andrew III's death, Ugrin marched into Požega County and captured his duchy.
Ugrin also extended his influence over Bács County during the era of Interregnum.
With this expansion, his dominion spread to the other bank of the Danube.
His biographer, Péter Galambosi doubted Engel's theory that the counties to the east of Syrmia (Keve, Krassó and Temes) belonged to Ugrin's province.

Because of his persistent loyalty to Charles, several historians did not list him among the oligarchs.
The young pretender was put under the protection of Ugrin Csák.
He resided in Bélakút Abbey (near present-day Petrovaradin, Serbia), which laid in the neighbor of Újlak, Ugrin's seat.
In his dominion, Charles performed judicial powers, donated lands and customs, granted privileges of tax exemption and judicial freedom, while the possessions of those who died without an heir returned to the Crown.
Charles donated lands and granted privileges in Ugrin's territory even after he left the province for Buda in 1307, when his troops seized the town.
Therefore, Attila Zsoldos draws a distinction between the "oligarchs" and "provincial lords" regarding the role of the royal power in the provincial administration.
While, accordingly, Ugrin was considered "only" provincial lord, Charles' other faithful partisans, Amadeus Aba or Stephen Ákos, who exercised sovereign rights in their domains but remained loyal to the king, were regarded as "loyal oligarchs".
While the Aba, Ákos and Kán sons rebelled against Charles after their fathers' deaths, Charles managed to restore full royal power without any resistance in Ugrin's domain after his death, despite the fact that he had a son, as royally appointed ispáns appear at the head of the counties which had formerly belonged to his province.

Ugrin's familiares entered the service of Charles, while retained the allegiance and loyalty to their lord, which reflects a power-sharing between the monarch and Ugrin Csák in his province.
Among them, Denis Zsadány was a long-time servant of Ugrin.
He was present, when the king restored the privileges and rights of the church of Buda in September 1308.
He attended the second coronation of Charles as the envoy of Ugrin in June 1309.
His skilled diplomat Benedict also represented him in the event; on his way to home, he was captured by the partisans of Henry II Kőszegi.
His remaining fate is unknown.
The renowned military leader, Paul Garai initially also belonged to Ugrin's household; he served as castellan of Požega Castle, when it was granted to the arriving Charles.
He participated in the war against Bohemia in the autumn of 1304.
The neighboring oligarch, Stephen Dragutin's troops pillaged Ugrin Csák's domains in 1307, but Garai made a counter-attack and defeated Dragutin's army, according to the narration of a royal charter issued on 13 October 1307.
Records of the destructions that Dragutin and his troops made in Valkó and Syrmia count
Ugrin Csák dominated the southern part of the Kingdom of Hungary, acquiring suzerainty over Upper Syrmia and other territories along the river Sava. Historian Gyula Pauler simply called him the "powerful lord of Syrmia" in the late 19th century. Bálint Hóman considered his influence extended to Trans-Drava, Syrmia and the Banate of Macsó. According to Pál Engel and Attila Zsoldos, his dominion extended in the territory from Požega to Temesvár (present-day Timișoara, Romania), and ruled over the counties of Požega, Valkó, Bács, Syrmia, Torontál, Keve and possibly Temes and Krassó. It is plausible that Ugrin dominated Syrmia County since the end of the 1270s as there were no records of any office-holders (ispáns) in the county since then. Around the same time, Ugrin also extended his influence in the neighboring Valkó County, where he built his centre Újlak (Ilok). Following his local rival Queen Tomasina's death, he acquired the whole county for himself. In 1303, the curialis comes of Valkó County styled himself as the "official" of Ugrin Csák, which demonstrates his lordship in the region. When Albertino Morosini left Hungary shortly after Andrew III's death, Ugrin marched into Požega County and captured his duchy. Ugrin also extended his influence over Bács County during the era of Interregnum. With this expansion, his dominion spread to the other bank of the Danube. His biographer, Péter Galambosi doubted Engel's theory that the counties to the east of Syrmia (Keve, Krassó and Temes) belonged to Ugrin's province.
Because of his persistent loyalty to Charles, several historians did not list him among the oligarchs. The young pretender was put under the protection of Ugrin Csák. He resided in Bélakút Abbey (near present-day Petrovaradin, Serbia), which laid in the neighbor of Újlak, Ugrin's seat. In his dominion, Charles performed judicial powers, donated lands and customs, granted privileges of tax exemption and judicial freedom, while the possessions of those who died without an heir returned to the Crown. Charles donated lands and granted privileges in Ugrin's territory even after he left the province for Buda in 1307, when his troops seized the town. Therefore, Attila Zsoldos draws a distinction between the "oligarchs" and "provincial lords" regarding the role of the royal power in the provincial administration. While, accordingly, Ugrin was considered "only" provincial lord, Charles' other faithful partisans, Amadeus Aba or Stephen Ákos, who exercised sovereign rights in their domains but remained loyal to the king, were regarded as "loyal oligarchs". While the Aba, Ákos and Kán sons rebelled against Charles after their fathers' deaths, Charles managed to restore full royal power without any resistance in Ugrin's domain after his death, despite the fact that he had a son, as royally appointed ispáns appear at the head of the counties which had formerly belonged to his province.
Ugrin's familiares entered the service of Charles, while retained the allegiance and loyalty to their lord, which reflects a power-sharing between the monarch and Ugrin Csák in his province. Among them, Denis Zsadány was a long-time servant of Ugrin. He was present, when the king restored the privileges and rights of the church of Buda in September 1308. He attended the second coronation of Charles as the envoy of Ugrin in June 1309. His skilled diplomat Benedict also represented him in the event; on his way to home, he was captured by the partisans of Henry II Kőszegi. His remaining fate is unknown. The renowned military leader, Paul Garai initially also belonged to Ugrin's household; he served as castellan of Požega Castle, when it was granted to the arriving Charles. He participated in the war against Bohemia in the autumn of 1304. The neighboring oligarch, Stephen Dragutin's troops pillaged Ugrin Csák's domains in 1307, but Garai made a counter-attack and defeated Dragutin's army, according to the narration of a royal charter issued on 13 October 1307. Records of the destructions that Dragutin and his troops made in Valkó and Syrmia count
Ugrin Csák