Ambrogio Landucci was born in Siena, Italy and ordained a priest in the Order of Saint Augustine.
In 1634, he was elected prior of the Monastery of the Holy Saviour in Lecceto, outside Siena which he enriched with a library and archives.
Landucci later served as one of two sacristans at the Apostolic Palace, a privilege reserved to the Augustinians.
On 30 August 1655, he was appointed during the papacy of Pope Alexander VII as Titular Bishop of Porphyreon.
[1][3] During a transfer of relics in 1656, Landucci found in the cemetery of Ciriaca (or San Lorenzo) on Via Tiburtina a wall mosaic, which he passed to Agostino Chigi, nephew of Pope Alexander VII.