Don John was sent in 1647 to
Naples, then in the throes of the
popular rising first led by
Masaniello, with a naval squadron and a military force, to support the viceroy. He ordered his land and sea forces to blockade the rebel held city while
Rodrigo Ponce de León, 4th Duke of Arcos inserted agents. Don John waited until the exhaustion of the insurgents and the follies of their French leader,
Henry II, Duke of Guise allowed him to move in and crush the remains of the revolt and drive out the, by then, despised French. He was next sent as viceroy to
Sicily, whence he was recalled in 1651 to complete the pacification of the
Principality of Catalonia, which had been in
revolt since 1640. On the way to Catalonia to assume his position, he
captured the French galleon Lion Couronné, with a squadron of galleys he had under his command. The high-handedness of the French, whom the Catalans had called in to help their revolt, had produced a reaction, and many switched their loyalties back to the Spanish King. By the time Don John assumed command, most of Catalonia had been recovered and he had not much more to do than to preside over the final
siege of Barcelona and the convention which terminated the revolt in October 1652. On both occasions, he played the peacemaker, and this sympathetic part, combined with his own pleasant manners, engaging personality, and a handsome person with bright eyes made him a popular royal favourite. In 1656, he was sent to command in
Flanders, then in revolt against his own sovereign. At the storming of the French camp at
Battle of Valenciennes in 1656, Don Juan Jose displayed great personal courage at the head of a brilliantly executed cavalry charge that caught the French totally by surprise. When, however, he took a part in the leadership of the army at the
Battle of the Dunes, fought against the French under
Turenne and the British forces sent by
Oliver Cromwell, he was decisively defeated and failed to raise the
Siege of Dunkirk, in spite of the efforts of
Louis, Grand Condé, whose invaluable advice he neglected, and the stubborn fight put up by his own troops. During 1661 and 1662, he fought
against the Portuguese in
Extremadura. The Spanish troops were ill-supplied and irregularly paid and in a rugged, hostile country. Morale was poor and they were untrustworthy but they were superior in numbers and some successes were gained. If Don John had not suffered from the indolence which
Edward Hyde, 1st Earl of Clarendon considered his chief defect, the Portuguese might have been hard-pressed. John's forces overran the greater part of southern Portugal, but in 1663, with the Portuguese forces
reinforced by a body of English troops, and put under the command of the Huguenot
Frederick Schomberg, 1st Duke of Schomberg, Don John was completely beaten at
Ameixial. Even so, he might not have lost the confidence of his father, if
Queen Mariana, mother of the sickly
Prince of Asturias Charles, the only surviving legitimate son of the King, had not regarded him with distrust and dislike. Don John was removed from command and sent to his estate at
Consuegra. ==Opposition to Queen Mariana of Spain==