Ottavio Piccolomini, 1st Duke of Amalfi (11 November 1599 – 11 August 1656) was an Italian nobleman whose military career included service as a Spanish general and then as a field marshal of the Holy Roman Empire.

[1] In 1624 he served for a short time again in the Spanish army besieging Breda and then as a lieutenant-colonel of Gottfried Heinrich Graf zu Pappenheim's cuirassier regiment in Northern Italy.

[1] Nineteenth-century authors were so impressed by Piccolomini's role in the battle of Lützen that they falsely ascribed to him the command of the entire Imperial left wing.

At the same time, Holk, who had played an even more crucial role in holding the Imperial army together at Lützen, was promoted to field marshal at Wallenstein's insistence, much to Piccolomini's chagrin.

[3] In May, Piccolomini accompanied Wallenstein and the main army on their way to Silesia in an attempt to compel the electors of Brandenburg and Saxony to join the emperor against the Swedes.

[1] On 24 January 1634 Ferdinand II signed a decree dismissing Wallenstein and instructed Count Gallas and Piccolomini to determine a course of action for removing the duke, but did not specifically demand his death.

[7] Piccolomini's achievements included relieving French sieges of Saint-Omer in 1638 together with Thomas Francis, Prince of Carignano and especially of Thionville on 7 July 1639 in a crushing victory over the Marquis de Feuquieres.

He was rewarded with the status of Count of the Empire in 1638[1] and the elevation to the office of privy councillor and the dukedom of Amalfi from King Philip IV of Spain in 1639.

[2] Despite own hopes to replace Matthias Gallas as main commander of the Imperials, Piccolomini was ordered to assist the emperor's brother, Archduke Leopold Wilhelm of Austria.

[2] After Banér's failed attempt to attack the Regensburg Reichstag in January 1641, Piccolomini and Gottfried Huyn von Geleen chased him with the united Imperial and Bavarian force.

He conducted the final campaign of the Thirty Years' War in which he and the Bavarians under Hunolstein stopped the Swedish and French advance at the rivers Inn and Danube and forced them to retreat out of Bavaria across the Lech.