King Stephen V of Hungary
- Born: Abt 1239
- Marriage: Unknown
- Died: 6 Aug 1272 about age 33
King Stephen V of Hungary (Hungarian: V. István, Slovak: tefan V) (1239 or 1240 - August 6, 1272), was the eldest son of Bela IV of Hungary, whom he succeeded in 1270.
His mother was Maria Laskarina, a daughter of Theodore I Lascaris of the Empire of Nicaea and Anna Angelina. Anna was a daughter of Alexius III Angelus and Euphrosyne Doukaina Kamaterina.
As crown prince Stephen had exhibited considerable ability, but also a disquieting restlessness and violence. In 1262 Stephen convinced his father Bela to give him twenty-nine counties as a reward of assistance in the war against Bohemia; hence Hungary was virtually divided into two kingdoms. He subsequently seized the southern banate of Macsó and defeated his father in the ensuing civil war. In 1268 he undertook an expedition against the Bulgarians, penetrating as far as Veliko Tarnovo and styling himself as king of Bulgaria.
Stephen's father, attempting to bind the powerful but pagan Cumans tribe more closely to the dynasty, arranged for Stephen's marriage, as a youth (about 1255), to Elizabeth, the daughter of the Cuman chieftain (named Koteny or Kuthens). Though Elizabeth, in preparation for the marriage, had been baptized and remained a Christian, western Europe almost universally considered Stephen as a semi-pagan. This hostility was felt as Stephen declared himself that everyone was his enemy for his accession to the Hungarian throne.
To secure foreign support, he formed a double matrimonial alliance with the Angevins, chief partisans of the pope. The first of these was the marriage in 1270 of his daughter Maria to Charles II of Naples (they became grandparents of Charles I of Hungary). The second alliance was the marriage of Stephen's infant son Ladislaus to Charles II's sister Elisabeth.
Byzantine Emperor Andronicus II married Anna, another of Stephen's daughters. Serbian king Stefan Dragutin married Katerina, yet another of Stephan's daughters.
Adversaries of Stephen, especially Ottokar II of Bohemia, believed that Stephen was too great a friend of the mighty Cumans (who could field 16,000 men) to be a true Catholic. Ottakar endeavoured with the aid of the Hungarian malcontents to conquer the western provinces of Hungary but they were utterly routed by Stephen in 1271 near Mosony. Ottakar relinquished all his conquests the same year in the peace of Pressburg.
Stephen died suddenly as he was raising an army to rescue his kidnapped infant son Ladislaus from his rebellious vassals.