Chiara was born in 1194 from a noble family of Assisi, daughter of Favarone di Offreduccio degli Scifi and Bernardino and Ortolana. It can certainly be said that a predominant part of the education of this girl is due to the great spirituality that pervaded the family environment of Chiara and in particular the figure of the mother who was among those ladies who had the great fortune to reach the Holy Land at following the crusaders.
The experience of the complete renunciation and preaching of St. Francis, the fame of Chiara's gifts for her fellow citizens, meant that these two great personalities understood perfectly the way to escape from the common world and give themselves completely to the contemplative life. The night after Palm Sunday, March 18, 1212, Chiara, accompanied by Pacifica di Guelfuccio, will go secretly to the Porziuncola, where she was expected by Francesco and his friars. Here Francesco dressed her in the Franciscan habit, cut her hair and consecrated her to penitence and took her to the Benedictine nuns of San Paolo in Bastia Umbra, where her father vainly tried to persuade her to return home. Clare took refuge later, on the advice of Francis, in the Church of San Damiano that became the Mother House of all her sisters called first "Poor Dame recluse of San Damiano" and, after the death of Chiara, Clarisse. Here he lived for forty-two years, almost always sick, starting to religious life many of his friends and relatives including his mother Ortolana and the sisters Agnese and Beatrice.
In 1215 Francis named her abbess and formed a first rule of the Order that was to expand throughout Europe. The great personality of Chiara did not go unnoticed by the high prelates, so much so that the papal legate, Cardinal Ugolino, formulated the first rule for subsequent monasteries and later was granted the privilege of poverty with which Chiara renounced all sorts of possessions. The firmness of character, the sweetness of his soul, the way of governing his community with the greatest charity and prudence, procured the esteem of the Popes who wanted to go to visit it. The death of Francis and the news that some monasteries accepted possessions and income embittered and alarmed Clare who increasingly sick wanted to save to the last poverty for his convent by composing a Rule similar to that of the Friars Minor, approved by Cardinal Rainaldo (later Pope Alexander IV) in 1252 and on the eve of his death by Innocent IV, he went to San Damiano to bring her the blessing and to give her the papal bull which confirmed her rule; the day after, 11 August 1253, Chiara dies, officiated by the Pope who wanted to sing for her not the office of the dead, but the festive one of the virgins. His body was buried in San Giorgio and later transferred to the church that bears his name. Although Innocent IV's intention was to canonize her immediately after death, the canonization bubble was reached in the autumn of 1255, after having followed all the formalities, through Alexander IV.