Uroš I, Grand Prince of Serbia

Uroš I (Урош I, ) was the Grand Prince (Veliki Župan) of the Grand Principality of Serbia from about 1112 to 1145.

Origin
Uroš I was the son of Marko, who was a son of Petrislav Vojislavljević and brother of Grand Prince Vukan, who had sworn an oath of loyalty to Constantine Bodin, the Grand Prince of Duklja, becoming his vassals. Marko, as the subordinate ruler, would have had his appanage in lands north of Raška, bordering the Kingdom of Hungary. The name Uroš itself, is most likely derived from the Hungarian word úr meaning "dominus" or "princeps", which is translated into the Slavic name 'Prvoslav', or 'Primislav', as seen in the case of Uroš II in Slavic sources. It is a possibility that Marko married a Hungarian wife.

War with Byzantium
In 1092, the Serb Army defeated the Byzantine Army led by the governor of Durazzo, sent by Alexius Comnenus. In 1093, Alexius himself led a larger Byzantine Army and marched towards Raška (i.e. Serbia), but Vukan heard of this and immediately sought peace, which Alexius quickly accepted as new problems arose in the east where the Cumans penetrated as far as Adrianople. As soon as the Emperor had departed, Vukan broke the treaty, conquering the Vardar and taking the cities of Vranje, Skoplje and Tetovo. In 1094 or 1095, the Emperor once again marched to the Serbs, capturing Lipljan. This time Vukan met with him in his tent and gave him some twenty hostages, including Uroš I and Stefan Vukan, as an oath of peace. Uroš was first mentioned in the contemporary Alexiad of Anna Komnene, a written account of the reign of her father Byzantine emperor Alexios I Komnenos.

Following the death of Vukan in 1112, Uroš succeeded as Grand Prince.

Civil War in Duklja
In 1113 or 1114, the Byzantine Army based in Durazzo invaded Duklja and captured the capital of Scutari. Duklja at the time was ruled by Prince Đorđe of Duklja (r. 1118), the son of Constantine Bodin. The Byzantines installed Grubeša Branislavljević after 1118, banishing Đorđe to Raška. Đorđe claimed protection of Uroš, and in the 1125 the two led an army against Grubeša, meeting in the Battle of Antivari. Grubeša was killed and Đorđe retained his realm, although not all of it. Small parts were ruled by cousins, among them the three brothers of Grubeša, who would soon quarrel with Đorđe. The Byzantines again invaded the coastlands of Duklja, giving nominal rule to Gradinja, resulting in a guerilla war in the woods. The second expedition captured Đorđe. He was taken to Constantinople where he died. Gradinja strengthened the ties with Serbia.

Diplomacy
In around 1130, he married his daughter, Jelena, to King Béla II of Hungary. Bela II, being blind, relied entirely on Jelena who acted as a co-ruler. Jelena is sourced as having decided to massacre 68 aristocrats at the Arad assembly, who had persuaded Coloman to blind her husband.

In 1137, Ladislaus II, the son of Béla II and Jelena, became the titular Ban of Bosnia.

When Bela II died on 13 February 1141, the eldest son Géza II ascended the throne, still a child. Therefore, Helena and her brother Beloš Vukanović, whom she had invited to the court, governed the Kingdom of Hungary until September 1146 when he came of age.

Beloš was the Ban of Croatia 1142-1158, under the Hungarian crown, and held the comes palatinus (Count palatine), the highest court title of the Kingdom.

Family
Uroš was married to Byzantine noblewoman Anna Diogenissa, who through her father was a granddaughter of Romanos IV Diogenes. They had the following issue: and possibly
 * Uroš II, Grand Prince of Serbia
 * Desa—Duke of Serbian Primorje, co-ruled Serbia with Uroš II
 * Beloš—Ban of Croatia and briefly Prince of Serbia
 * Helena, Queen of Hungary and Croatia (d. after 1146), married King Béla II of Hungary
 * Marija, married Conrad II of Znojmo. They had five children.
 * Zavida - Duke of Zahumlje. In a Zadar act, Beloš's brother is named "Stefan"; that name is found in the sons of Zavida.