She was daughter of Bela IV. king of Hungary, and Mary, daughter
to Theodorus Lascharis, emperor of Constantinople: was married
1239 to Boleslas the Chaste, sovereign of Lesser Poland, or of the
palatinates of Cracow, Sandomire, and Lublin; but by mutual consent
lived in perpetual chastity. Prayer, mortification, alms, and daily
attendance on the poor in the hospitals, employed her time. Boleslas
dying in 1279, she took the veil in the great monastery of Sandecz,
which she had lately built for nuns of the Order of St. Clare. She
died on the 24th of July in 1292. She was venerated with singular
piety in the diocess of Cracow and several other parts of Poland, and
her name was solemnly inscribed among the saints by Alexander VIII.
in 1690. See her life by John Longinus commonly called Dlugos, with
remarks by Bosch the Bollandist, t. 5, Julij, p. 661.