Ambrose of Siena or Sienna (born Ambrogio Sansedoni; 16 April 1220 – 20 March 1287) was an Italian Dominican teacher, missionary and diplomat.

Biography

Ambrose was born at Sienna on 16 April 1220, to the noble family of Sansedoni. When he was around a year old, Ambrose was cured of a congenital deformity, in the Dominican church of St.

Mary Magdalene Mary Magdalene (sometimes called Mary of Magdala, or simply the Magdalene or the Madeleine) was a woman who, according to the four canonical gospels, traveled with Jesus as one of his followers and was a witness to crucifixion of Jesus, his cr ...

. As a child and youth he was noted for his love of charity, exercised especially towards pilgrims, the sick in hospitals, and prisoners. He entered the novitiate of the Dominican convent in his native city at the age of seventeen, was sent to Paris to continue his philosophical and theological studies under Albert the Great and had for a fellow-student there,

Thomas Aquinas Thomas Aquinas ( ; ; – 7 March 1274) was an Italian Dominican Order, Dominican friar and Catholic priest, priest, the foremost Scholasticism, Scholastic thinker, as well as one of the most influential philosophers and theologians in the W ...

.Fitzgerald, Edward. "Bl. Ambrose of Sienna." The Catholic Encyclopedia. Vol. 1. New York: Robert Appleton Company, 1907. 24 Dec. 2012
/ref> In 1248 he was sent with Thomas to

Cologne Cologne ( ; ; ) is the largest city of the States of Germany, German state of North Rhine-Westphalia and the List of cities in Germany by population, fourth-most populous city of Germany with nearly 1.1 million inhabitants in the city pr ...

, where he taught in the Dominican schools. In 1260 he was one of the band of missionaries who evangelized

Hungary Hungary is a landlocked country in Central Europe. Spanning much of the Pannonian Basin, Carpathian Basin, it is bordered by Slovakia to the north, Ukraine to the northeast, Romania to the east and southeast, Serbia to the south, Croatia and ...

. Six years later Sienna was put under an interdict for having espoused the cause of the Emperor Frederick II, then at enmity with the

Holy See The Holy See (, ; ), also called the See of Rome, the Petrine See or the Apostolic See, is the central governing body of the Catholic Church and Vatican City. It encompasses the office of the pope as the Bishops in the Catholic Church, bishop ...

. The Siennese petitioned Ambrose to plead their cause before the Sovereign Pontiff, and so successfully did he do this that he obtained for his native city full pardon and a renewal of all her privileges. The Siennese soon cast off their allegiance; a second time Ambrose obtained pardon for them. He brought about a reconciliation between King

Conradin Conrad III (25 March 1252 – 29 October 1268), called ''the Younger'' or ''the Boy'', but usually known by the diminutive Conradin (, ), was the last direct heir of the House of Hohenstaufen. He was Duke of Swabia (1254–1268) and nominal King ...

of Germany and Pope Clement IV. Around this time he was chosen bishop of his native city, but he declined the office. For a time, he devoted himself to preaching the Eighth Crusade; and later, at the request of Pope Gregory X, caused the studies which the late wars had practically suspended to be resumed in the Dominican convent at Rome. After the death of Pope Gregory X, he retired to one of the convents of his order, whence he was summoned by Innocent V and sent as

papal legate 300px, A woodcut showing Henry II of England greeting the Pope's legate. A papal legate or apostolic legate (from the ancient Roman title '' legatus'') is a personal representative of the Pope to foreign nations, to some other part of the Catho ...

Tuscany Tuscany ( ; ) is a Regions of Italy, region in central Italy with an area of about and a population of 3,660,834 inhabitants as of 2025. The capital city is Florence. Tuscany is known for its landscapes, history, artistic legacy, and its in ...

. He restored peace there between

Florence Florence ( ; ) is the capital city of the Italy, Italian region of Tuscany. It is also the most populated city in Tuscany, with 362,353 inhabitants, and 989,460 in Metropolitan City of Florence, its metropolitan province as of 2025. Florence ...

and

Pisa Pisa ( ; ) is a city and ''comune'' (municipality) in Tuscany, Central Italy, straddling the Arno just before it empties into the Ligurian Sea. It is the capital city of the Province of Pisa. Although Pisa is known worldwide for the Leaning Tow ...

and also between the dogal republics of

Venice Venice ( ; ; , formerly ) is a city in northeastern Italy and the capital of the Veneto Regions of Italy, region. It is built on a group of 118 islands that are separated by expanses of open water and by canals; portions of the city are li ...

and

Genoa Genoa ( ; ; ) is a city in and the capital of the Italian region of Liguria, and the sixth-largest city in Italy. As of 2025, 563,947 people live within the city's administrative limits. While its metropolitan city has 818,651 inhabitan ...

, another pair of commercial rivals within Italy. He died at Sienna on 20 March 1287. His name was inserted in the

Roman Martyrology The ''Roman Martyrology'' () is the official martyrology of the Catholic Church. Its use is obligatory in matters regarding the Roman Rite liturgy, but dioceses, countries and religious institutes may add duly approved appendices to it. It provid ...

in 1577. His biographers exhibit his life as one of perfect humility. He loved poetry. He was a renowned

preacher A preacher is a person who delivers sermons or homilies on religious topics to an assembly of people. Less common are preachers who Open-air preaching, preach on the street, or those whose message is not necessarily religious, but who preach com ...

. His oratory, simple rather than elegant, was most convincing and effective. His sermons, although once collected, are not extant.

References

{{DEFAULTSORT:Ambrose of Siena 1220 births 1287 deaths Italian Dominicans Italian beatified people People from Siena 13th-century venerated Christians Italian Roman Catholic missionaries Dominican missionaries Roman Catholic missionaries in Hungary