Ambrose of Siena
Italian teacher and diplomat (1220–1287)
Who they were
Ambrose Sansedoni was born at Siena on 16 April 1220 of a noble family and as an infant was cured of a congenital deformity in the Dominican church. As a youth he was known for his charity to pilgrims, the sick and prisoners.
He entered the Dominicans at seventeen, studied in Paris under Albert the Great with St Thomas Aquinas as a fellow student, and taught with Thomas at Cologne. In 1260 he was a missionary in Hungary, and he worked to reconcile Siena with the Holy See when it was under interdict. He died at Siena in 1286.
The miracles
He is honoured as Blessed by long-standing veneration; the Catholic Encyclopedia does not describe a formal cause.
Why that counted as sanctity
A Dominican preacher and peacemaker, friend of St Thomas Aquinas.
Connected on this site
- Thomas Aquinas Saint“He entered the Dominicans at seventeen, studied in Paris under Albert the Great with St Thomas Aquinas as a fellow student, and taught with Thomas at Cologne.” — this site's research
- Catholic Encyclopedia (1913), via New Advent - Blessed Ambrose of Siena
- Wikidata Q4741879 — dates, feast day and identifiers (CC0)
- English Wikipedia — Ambrose of Siena (CC BY-SA)
Checked against the sources listed on 21 September 2026. Corrections welcome.