Title: Béla IV of Hungary
Content:  Béla IV (1206 – 3 May 1270) was King of Hungary and Croatia between 1235 and 1270, and Duke of Styria from 1254 to 1258. As the oldest son of King Andrew II, he was crowned upon the initiative of a group of influential noblemen in his father's lifetime in 1214. His father, who strongly opposed Béla's coronation, refused to give him a province to rule until 1220. In this year, Béla was appointed Duke of Slavonia, also with jurisdiction in Croatia and Dalmatia. Around the same time, Béla married Maria, a daughter of Theodore I Laskaris, Emperor of Nicaea. 
Title: Béla IV of Hungary
Content:  Béla was the oldest son of King Andrew II of Hungary by his first wife, Gertrude of Merania. He was born in the second half of 1206. Upon King Andrew's initiative, Pope Innocent III had already appealed to the Hungarian prelates and barons on 7 June to swear an oath of loyalty to the King's future son. Queen Gertrude showed blatant favoritism towards her German relatives and courtiers, causing widespread discontent among the native lords. Taking advantage of her husband's campaign in the distant Principality of Halych, a group of aggrieved noblemen seized and murdered her in the forests of the Pilis Hills on 28 September 1213. King Andrew only punished one of the conspirators, a certain Count Peter, after his return from Halych. Although Béla was a child when his mother was assassinated, he never forgot her and declared his deep respect for her in many of his 
Title: Béla IV of Hungary
Content:  regions—was established along the southern frontier of Hungary in the 1250s. Béla's relationship with his oldest son and heir, Stephen, became tense in the early 1260s, because the elderly king favored his daughter Anna and his youngest child, Béla, Duke of Slavonia. He was forced to cede the territories of the Kingdom of Hungary east of the river Danube to Stephen, which caused a civil war lasting until 1266. Nevertheless, Béla's family was famed for his piety: he died as a Franciscan tertiary, and the veneration of his three saintly daughters—Kunigunda, Yolanda, and Margaret—was confirmed by the Holy See.
Title: Béla (given name)
Content: Béla of Hungary ; Béla I of Hungary (1020–1063), King of Hungary ; Béla II of Hungary (1109–1141), King of Hungary and Croatia ; Béla III of Hungary (1148–1196), King of Hungary and Croatia ; Béla IV of Hungary (1206–1270), King of Hungary and Croatia ; Béla V of Hungary (Otto III of Bavaria; 1261–1312), Duke of Lower Bavaria and King of Hungary and Croatia ; Béla of Macsó (1243–1272), Duke of Macsó and Bosnia ; Bela of Saint Omer (?–1258), French knight, Lord of one half of Thebes ; Bela of Britonia (fl. 675), Galician clergyman, Bishop of Britonia ; Béla Nagy Abodi (1918–2012), Hungarian painter ; 
Title: Béla, Duke of Slavonia
Content:  Béla was the youngest child and the second son of King Béla IV of Hungary. His mother was Maria Laskarina, daughter of Theodore I Laskaris, Emperor of Nicaea. The year of his birth is uncertain, but he was his parents' youngest child. Taking into account that his sister, Margaret was born in 1242, Mór Wertner, Gyula Kristó and other historians write that Béla was born around 1243. Béla himself stated in a charter of 1269 that "we has not turned twenty-five, we are about twenty", suggesting that he had actually been born around 1249. King Béla's letter to Pope Innocent IV, which was written in about 1254, contains the first record of Béla's life. The letter refers to a plan of the child Béla's marriage with an unnamed niece of the Pope. However, the marriage never took place because of the death of Pope Innocent shortly thereafter. Béla's tutor was Andrew Hont-Pázmány in 1256. Berke Khan proposed an alliance to Béla IV in 1259 by offering to marry one of his daughters to a son of Béla (i.e. his namesake younger son, the only one who had not yet been married), but he refused the Khan's offer.
Title: Béla I of Hungary
Content:  Most Hungarian chronicles, including Simon of Kéza's Gesta Hungarorum and the Illuminated Chronicle, record that Béla's father was Ladislas the Bald, a cousin of Stephen, the first King of Hungary. However, many of the same sources add that it "is sometimes claimed" that Béla and his two brothers—Levente and Andrew—were in fact the sons of Ladislaus the Bald's brother, Vazul. The chronicles also refer to gossip claiming that the three brothers were their father's illegitimate sons, born to "a girl from the Tátony clan". Modern historians, who accept the latter reports' reliability, unanimously write that the three brothers were the sons of Vazul and his concubine. Béla was born between 1015 and 1020. It is debated whether Béla was a second or a third son. The former view is represented, for example, by the Polish historian Wincenty Swoboda, and the latter by the Hungarian scholars Gyula Kristó and Ferenc Makk. Kristó and Makk write that Béla's name "most probably" derived from the Turkish adjective bujla ("noble"). However, the name may also be connected to the Slavic word for white (bjelij) or to the Biblical name Bela.
Title: Béla IV of Hungary
Content:  Béla's wife, Maria Laskarina was born in 1207 or 1208, according to historian Gyula Kristó. She died in July or August 1270. Their first child, Kunigunda, was born in 1224, four years after her parents' marriage. She married to Boleslaw the Chaste, Duke of Cracow in 1246. A second daughter, Margaret followed Kunigunda in about 1225; she died unmarried before 1242. The third daughter of Béla, Anna was born around 1226. She and her husband, Rostislav Mikhailovich were especially favored by Béla. Her great-grandson, Wenceslaus—a grandson of her daughter, Kunigunda by King Ottokar II of Bohemia—was King of Hungary from 1301 to 1305. Béla's fourth child, Catherina died unmarried before 1242. Next, Elisabeth was born; she was given 
Title: Béla I of Hungary
Content:  Béla I the Boxer or the Wisent (I. Bajnok or Bölény Béla, Belo I.; c. 1015 – 11 September 1063) was King of Hungary from 1060 until his death. He descended from a younger branch of the Árpád dynasty. Béla's baptismal name was Adalbert. He left Hungary in 1031, together with his brothers, Levente and Andrew, after the execution of their father, Vazul. Béla settled in Poland and married Richeza (or Adelaide), daughter of Polish king Mieszko II Lambert. He returned to his homeland upon the invitation of his brother Andrew, who had in the meantime been crowned King of 
Title: Béla I of Hungary
Content:  Béla married, in about 1033, a daughter of King Mieszko II of Poland. According to Makk, her name was either Richesa or Adelheid. Their eldest children, Géza and Ladislaus—who became kings of Hungary in 1074 and 1077, respectively—were born in Poland in the 1040s. Béla's third son, Lampert, was born after Béla's return to Hungary. Lampert was followed by a daughter named Sophia, who was first married to Margrave Ulric I of Carniola, and later to Duke Magnus of Saxony. Her younger sister, Euphemia, became the wife of Duke Otto I of Olomouc. Béla's third daughter, Helena, was the wife of King Demetrius Zvonimir of Croatia. An unnamed daughter of Béla became the first wife of a Hungarian nobleman, Lampert of the Clan Hont-Pázmány. According to the historian Martin Dimnik, Béla also fathered a fifth daughter, Lanka, who was the wife of Prince Rostislav Vladimirovich of Tmutarakan. The following family tree presents Béla's ancestry, his offspring, and some of his relatives mentioned in the article. *A Khazar, Pecheneg or Volga Bulgarian lady. **Györffy writes that she may have been a member of the Bulgarian Cometopuli dynasty. ***Lanka is not mentioned as Béla I's daughter by all specialists.
Title: Béla IV of Hungary
Content:  youngest (namesake) son, Béla was born between around 1243 and 1250. The Greater Legend of Saint Elisabeth of Hungary (Béla's sister) described Béla's family as a company of saints. It wrote that the "blessed royal family of the Hungarians is adorned with resplendent pearls that irradiate all the earth". In fact, the Holy See sanctioned the veneration of three daughters of Béla and his wife: Kunigunda was beatified in 1690, Yolanda in 1827; and Margaret was canonized in 1943. A fourth daughter, Constance also became subject to a local cult in Lemberg (Lviv, Ukraine), according to the Legend of her sister, Kunigunda. The following family tree presents Béla's offspring, and some of his relatives mentioned in the article.

Question: Who is the father of Béla IV of Hungary?
Answer: Andrew II of Hungary.