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Family

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 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 daughter, Catherina died unmarried before 1242. Next, Elisabeth was born; she was given in marriage to Henry XIII, Duke of Bavaria in about 1245. Her son, Otto was crowned King of Hungary in 1305, but was forced to leave the country by the end of 1307. Béla's sixth daughter Constance married, around 1251, Lev Danylovich, second son of Prince Daniil Romanovich of Halych. Béla's seventh daughter, Yolanda became the wife of Bolesław the Pious, Duke of Greater Poland.

Béla's first son, Stephen was born in 1239. He succeeded his father. Béla's youngest daughter, Margaret was born during the Mongol invasion in 1242. Dedicated to God by her parents at birth, she spent her life in humility in the Monastery of the Blessed Virgin on Rabbits' Island and died as a Dominican nun. The King's 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.