At 25 years of age, he took the throne from his brother Vladislav, and despite not having support from in-laws as was the case with his brothers, he immediately ruled energetic and determined. Prior to his accession, the land had been looted by the Tatars and there were widespread internal conflicts; Uroš managed in a short time to resolve all important issues in the state and in its foreign policy. The situation in Europe and in the Balkans were quite favourable for Serbia, which he very cleverly used for his benefit. During his reign Serbia significantly strengthened itself and progressed in every way. Uroš correctly determined the direction in political pretensions through penetrating the south in Macedonia and conflict with Hungary in
Podunavlje. The land was politically and militarily prepared for serious politics and definitive fortification of Serbia and the Serb people in the Vardar valley and the middle Podunavlje. Apart from this, Uroš also correctly determined the direction of Serbian trade politics, as he on several occasions in his fight against the
Republic of Ragusa wanted to eliminate Ragusan brokerage and exploitation in his state. Particular significance in his domestic politics is that he strongly stressed the state principle above all else, and subordinated the churches (both Orthodox and Catholic) to state interests. He was instrumental in the definite solution to the conflict between the archbishoprics of Bar and Dubrovnik regarding power in Serbia, resolved in favour of Bar. Uroš was the first to begin exploiting the mines, which would later become one of the main sources of material wealth and power of the Serbian state in the Middle Ages. As a first result of the opening of mines came the forging of Serbian coins, which he first minted on the Venetian model. He protected and assisted literature and writers; i.e. gave impetus to the preparation of a new, more comprehensive and ornate biography of his grandfather Nemanja, whom he fully modeled himself after. King Uroš lived a modest patriarchal life, happy and content within his family, and he in contrast to the splendor of the Byzantine court, proudly emphasized modesty to the Byzantine deputies, which dominated at his court, where everyone had to work. In foreign policy Uroš skillfully used to his advantage the conflict between the
Despotate of Epirus and the
Empire of Nicaea, two Greek states, both of which sought to inherit the Byzantine Empire and take Constantinople from the
Latin Empire. But when the Latin Empire fell, and Emperor
Michael Palaiologos of Nicaea took Constantinople, Uroš began to coalite with his wife's cousin,
Charles of Anjou, who wanted to recapture Constantinople, and through that alliance take as much Byzantine land as possible. Via Charles, who had family ties with the Hungarian kings, Uroš at the end of his reign also approached Hungary, with whom he long had been in a bad relation, and married his eldest son and heir,
Stefan Dragutin, to Catherine, the daughter of Hungarian king
Stephen V. Pushed by his in-laws, with the help of the army he received from Hungary, Dragutin, unhappy with not getting more participation in the government, revolted and defeated his father and took over the throne. Uroš retired with his loyals to
Hum, where, disappointed, dissatisfied and angry, he died soon thereafter. ==Economic development==