Biography of St. Catherine of Siena 

Feast day: April 29

St. Catherine of Siena, Doctor of the Church

Catherine Benincasa (1347-1380), the 25th child of a wool dyer in northern Italy, started having mystical experiences when she was only 6, seeing guardian angels as clearly as the people they protected. She became a Dominican tertiary when she was 16, and continued to have visions of Christ, Mary, and the saints. She gained reknown in her native Siena for her visions and gathered a spiritual family called Caternati whom she advised.

St. Catherine was one of the most brilliant theological minds of her day, although she never had any formal education. In 1376, she went to Avignon to plead with Pope Gregory XI to return to Rome, to make peace with Florence, and to crusade against the Muslims in the Holy Land. When she died at 33 years of age in 1379, she was endeavoring to heal the Great Western Schism.

In 1375 Our Lord give her the Stigmata, which was visible only after her death. Her body was found incorrupt in 1430. She was canonized in 1461 by Pope Pius II. St. Catherine's letters, and a treatise called "a dialogue" are considered among the most brilliant writings in the history of the Catholic Church. Her most famous work is Dialogo, published c. 1375, which reflects her visions and mystical experiences. Several of her letters are extant.

Sources:

http://www.catholic.org/saints/saint.php?saint_id=9

http://www2.evansville.edu/ecoleweb/glossary/cathsiena.html