Dominican Tertiary, born in Siena, 25 March, 1347; died in Rome, 29 April, 1380.

St. Catherine of Siena was the youngest but one of a very large family. Her father, Giacomo di Benincasa, was a dyer and her mother, Lapa, was the daughter of a local poet.

From her childhood Catherine began to see visions and to practise extreme austerities. At the age of seven she consecrated her virginity to Christ; in her 16th year she took the habit of the Dominican Tertiaries, and renewed the life of the anchorites of the desert in a little room in her father's house. After three years of celestial visitations and familiar conversations with Christ, she underwent the mystical experience known as the "spiritual espousals", probably during the carnival of 1366.

She now rejoined her family, began to tend the sick, especially those afflicted with the most repulsive diseases, to serve the poor, and to labour for the conversion of sinners. Though always suffering terrible physical pain, living for long intervals on practically no food save the Blessed Sacrament, she was ever radiantly happy and full of practical wisdom no less than the highest spiritual insight.

All her contemporaries bear witness to her extraordinary personal charm, which prevailed over the continual persecution to which she was subjected even by the friars of her own order and by her sisters in religion.

During the summer of 1370 she received a series of special manifestations of Divine mysteries, which culminated in a prolonged trance, a kind of mystical death, in which she had a vision of Hell, Purgatory, and Heaven, and heard a Divine command to leave her cell and enter the public life of the world. She was consulted by the papal legates about the affairs of the Church. 

She implored the pope, Gregory XI, to leave Avignon, to reform the clergy and the administration of the Papal States, and ardently threw herself into his design for a crusade, in the hopes of uniting the powers of Christendom against the infidels, and restoring peace to Italy by delivering her from the wandering companies of mercenary soldiers. While at Pisa, on the fourth Sunday of Lent, 1375, she received the Stigmata, although, at her special prayer, the marks did not appear outwardly in her body while she lived.

The works of St. Catherine of Siena rank among the classics of the Italian language, written in the beautiful Tuscan vernacular of the fourteenth century. Her writings consist of the "Dialogue", or "Treatise on Divine Providence". 

The key-note to Catherine's teaching is that man, whether in the cloister or in the world, must ever abide in the cell of self-knowledge, which is the stable in which the traveller through time to eternity must be born again.

Her primary feast is on the 29th of April.