Yolanda (Hungarian Jolán, Polish Jolenta) was born in 1235 at Esztergom to King Béla IV of Hungary and Queen Maria Laskarina — the younger sister of St. Kinga of Poland (1234–1292).
In 1256, at the age of 21, Yolanda was married to Bolesław the Pious of Kalisz (1224–1279) — Piast prince of Greater Poland (Wielkopolska).
Yolanda and Bolesław established the royal court at Gniezno-Kalisz and produced three daughters (Hedwig, Elisabeth, and Anna). During the period, they undertook extensive Catholic charitable and monastic patronage — patrons of the Franciscan Order in Greater Poland, founders of multiple Franciscan churches and convents.
After Bolesław's death in 1279, Yolanda undertook the Poor Clare vocation — in institutional parallel with her older sister Kinga (also widowed in 1279 and taking the Poor Clare habit that same year) and her sister-in-law-once-removed Bl. Salomea (Poor Clare from 1245).
Yolanda entered the Poor Clare Monastery of Stary Sącz (with her sister St. Kinga) around 1280, then moved to found her own Poor Clare Monastery at Gniezno — the primatial see of Poland — serving as abbess of Gniezno until her death on June 17, 1298.
The three Polish royal Poor Clare saints — Bl. Salomea (1211–1268), St. Kinga (1234–1292), and Bl. Yolanda (1235–1298) — institutionally established the Polish royal-Piast-dynasty Poor Clare tradition of the royal-lay-becoming-monastic culture that would extend through the medieval Polish Catholic centuries.

