With the recommencement of war in Flanders in 1621, Brancaccio returned there. In 1623, in recognition of his services to the Spanish monarchy, Philip IV of Spain created him Marquess of Montesilvano. In 1626 he became "maestro di campo generale" of the Genoese forces in their conflict with Savoy over the Marquisate of Zuccarello. From 1627 to 1630 he was in Spain as an adviser to the Council of War in Madrid. He returned to Italy in 1630 to command forces in the War of the Mantuan Succession, and when that war was settled by treaty in 1631 he travelled to Flanders for a fourth time. He commanded the garrison defending Maastricht during the siege of 1632. In that year or the following Philip IV named him a councillor of state. In 1633 he travelled via Lombardy to Barcelona. Given command of the army of Roussillon (then part of the Crown of Aragon), he died at Perpignan in December 1637.