Antonio Piccolomini was the son of Andrea Piccolomini, of the lords of Modanella, in the same branch of the Piccolomini family as Pope Pius II. He was ordained a priest in the
Order of Saint Benedict. He was succeeded by Francesco Todeschini-Piccolomini (
Pope Pius III), who was named Abbot Commendatory in 1458. On 18 September 1458, Antonio was appointed
Bishop of Siena by the newly-elected
Pope Pius II, who had just vacated the bishopric of Siena. Pius II granted him the privilege of being consecrated a bishop by any bishop he chose who was in communion with Rome. As bishop-elect, he took possession of his new diocese on 28 September 1458. On 16 April 1459, he was
consecrated bishop, though the names of the consecrators remain unknown. On 23 April 1459,
Pope Pius II elevated the diocese of Siena, of which he had recently been the bishop, to the rank of Metropolitan
Archbishop of Siena. Antonio Piccolomini served as Archbishop of Siena a total of seventeen months, until his death on 8 November 1459. He was succeeded on 6 February 1460 by Francesco Todeschini-Piccolomini. == References ==