Béla II of Hungary

Massacre of Béla II's opponents on the orders of Queen Helena at the assembly of Arad in 1131

Béla's blindness prevented him from administering his kingdom without assistance.[17][18] He put his trust in his wife and her brother Beloš.[18] Both royal and private charters from Béla's reign emphasize Queen Helena's pre-eminent role in the decision-making process, proving that the king regarded his wife as his co-ruler.[19] According to the Illuminated Chronicle, at "an assembly of the realm near Arad"[20] in early to mid-1131, Queen Helena ordered the slaughter of all noblemen who were accused of having suggested the blinding of her husband to King Coloman.[17][21] Béla distributed the goods of the executed magnates between the newly established Arad Chapter and the early 11th-century Óbuda Chapter.[22]

Béla's was on good terms with the Holy Roman Empire, jeopardizing the interests of Boleslaw III of Poland who had been warring with the empire.[23] The Polish monarch decided to support a pretender to the Hungarian crown named Boris.[23] Boris was born to King Coloman's second wife Euphemia of Kiev after his mother was repudiated for adultery.[17] After Boris arrived in Poland, a number of Hungarian noblemen joined him.[24] Others sent messengers to Boris "to invite him that he should come and with their help claim the kingdom for himself",[25] according to the Illuminated Chronicle.[26][24]

Accompanied by Polish and Rus' reinforcements, Boris broke into Hungary in mid-1132.[24] Béla entered into an alliance with Leopold III, Margrave of Austria.[27] Before launching a counter-attack against Boris, Béla convoked a council on the river Sajó.[24] The Illuminated Chronicle relates that the King asked "the eminent men of Hungary" who were present if they knew whether Boris "was a bastard or the son of King Coloman".[25][28] The King's partisans attacked and murdered all those who proved to be "disloyal and divided in their minds"[25] during the meeting.[29] Boris, who thought that the majority of the Hungarian lords supported his claim, in vain sent one of his partisans to Béla's camp to incite the King's retinue to mutiny.[29]

[Samson] proposed to go to the assembly of the King and there openly and publicly insult him. All approved and [Boris] himself, misled by empty hope, gave him great thanks; for he wanted to complete what he had begun, and he thought that after the King had been thus insulted the kingdom would be his. The King had taken up his station near the river [Sajó], and as he sat in his tent with his nobles and soldiers, behold, [Samson] entered and said to the King: "Vile dog, what are you doing with the kingdom? It is better that your lord [Boris] have the kingdom and for your to live in your monastery, as your father did." There was commotion among the nobles of the realm, and Johannes, the son of Otto, the King's notary ... , said to Count Bud: "Why are we waiting? Why do we not seize him?" As they made to seize him, he hastily leapt upon a horse and fled.

— The Hungarian Illuminated Chronicle[30]

Béla tried to persuade the Polish monarch to stop supporting the pretender.[31] However, Boleslaw remained loyal to Boris.[32] In the decisive battle, which was fought on the river Sajó on 22 July 1132, the Hungarian and Austrian troops defeated Boris and his allies.[23][33]

Boleslaw III of Poland could not assist Boris after the Battle of the Sajó.[33] Béla's allies—Soběslav I of Bohemia and Volodimirko of Peremyshl—invaded Poland each year between 1132 and 1135.[23][33] Soběslav regularly—in 1133, 1134, 1137, and 1139—visited Béla's court.[34] The Czech monarch even persuaded Lothar III, Holy Roman Emperor to force Boleslaw III to abandon Boris and recognize Béla's rule in Hungary in August 1135.[33][35]

The seal of Béla II

Hungary adopted an expansionist policy after Boris's attempts to dethrone Béla.[34] The chronicler Thomas the Archdeacon relates that Gaudius, who became Archbishop of Split in 1136, "enjoyed great favor with the kings of Hungary" and "often visited their court".[36][37] The report suggests that Split accepted Béla II's suzerainty around 1136, but this interpretation of the sources is not universally accepted by historians.[37][34] The exact circumstances surrounding the submission of Bosnia are unknown but the region seems to have accepted Béla's suzerainty without resistance by 1137.[38] Historian John V. A. Fine writes that the northeastern regions of the province formed part of Queen Helena's dowry.[18] The Hungarian army penetrated into the valley of the Rama River, a tributary of the Neretva River, in about 1137.[33][17] Although Béla assumed the title King of Rama in token of the new conquest, the permanent occupation of the region is not proven.[17]

Hungarian troops participated in a campaign launched by Grand Prince Yaropolk II of Kiev against Vsevolod of Kiev in 1139.[34][39] Béla strengthened his alliance with the Holy Roman Empire.[34] For this purpose, he gave financial support to Otto of Bamberg's missions among the Pomeranians and arranged the engagement of his daughter Sophia with Henry, son of the new German king Conrad III in June 1139.[34]

Béla's denar

According to the Hungarian chronicles, in the last few years of his life Béla became a drunkard.[17] His courtiers took advantage of his drunkenness to receive grants from him.[40] When he was in an alcoholic stupor, he sometimes ordered the execution of innocent men.[40] Béla died on 13 February 1141, "on the Ides of February, a Thursday".[41][40] He was buried in the Székesfehérvár Cathedral.[40]

After King Bela had been established in his rule of the kingdom, he indulged himself much with wine. His courtiers found that whatever they asked of the King in his drunkenness he would grant, and after his drunkenness he could not take it back. In his drunkenness he delivered Poch and Saul, who were in religious orders, into the hands of their enemies, and they were killed without cause.

— The Hungarian Illuminated Chronicle[42]