The
War of the Spanish Succession (1701–1714) broke out after
Charles II of Spain, the last
Habsburg king of Spain, died without heir. Dillon and his regiment were first sent to the Rhine in 1701 where he served under
François de Neufville, duc de Villeroy, but Villeroy and Dillon were soon transferred to northern Italy where France and its ally Savoy were trying to seize the
Duchy of Milan, which belonged to Spain. French troops under the command of Marshal
Nicolas Catinat fought the Austrians under
Prince Eugene of Savoy. However, after Catinat lost the
skirmish of Carpi on 9 July 1701, the command of the French troops in Italy was given to Villeroy under whom Catinat then served as second in command. On 1 September 1701 Prince Eugene defeated Villeroy at
Chiari. On 16 September 1701 James II died at Saint-Germain-en-Laye and was succeeded by
James Francis Edward Stuart, James III for the Jacobites, the Old Pretender for the supporters of
William III in England, who was succeeded by
Queen Anne on 8 March 1702. Eugene's next move in northern Italy was to surprise Villeroy in his winter quarters in
Cremona on the night of 31 January to 1 February 1702, an action also called the
Battle of Cremona. Villeroy was taken prisoner, but the French were saved from defeat by Dillon's and Bourke's Irish regiments, who held the Po-gate and the bridge over the
River Po against the Austrians, thus preventing Eugene from effecting his junction with the troops he had on the other side of the river. Eventually, Eugene could not hold the town against its garrison and had to retreat. Villeroy was replaced with the duc de Vendôme, under whom Dillon had already served at Barcelona. Under Vendôme Dillon and his regiment fought in the battles of
Santa-Vittoria on 26 July 1702, and
Luzzara on 15 August 1702. On 1 October 1702 Dillon was promoted to brigadier. In 1703 Vendôme tried to effect a junction with the Bavarians, allied with the French against Austria, through the
Tyrol and penetrated as far as
Trent. Dillon took the town of
Riva at the northern tip of
Lake Garda. However, on 13 August 1704 Marlborough and Eugene beat the French and Bavarians at
Blenheim. Savoy switched side and Vendôme had to retreat. In 1704 Dillon, aged 34, was promoted to
maréchal de camp. On 16 August 1705 Vendôme repulsed Eugene at
Cassano. Three Irish regiments, including Dillon's, played a key-role in halting Eugene's attack. Dillon was made a commander of the
Order of Saint Louis. On 23 May 1706
Marlborough beat Villeroy at
Ramillies in the Spanish Netherlands. Thereupon, Louis XIV ordered Vendôme with a big part of the Armée d'Italie to Flanders to redress the situation there. Dillon and his regiment stayed behind in Northern Italy.
Philippe II, Duke of Orléans, who would rule France as Regent from 1715 to 1723, replaced Vendôme in Italy, taking up his new position in July. Together with
Jacques Eléonor Rouxel de Grancey, comte de Médavy, Dillon defeated at the
Battle of Castiglione on 9 September 1706 a Hessian unit under
Prince Frederick of Hesse-Kassel that had arrived too late from Germany to join the main body of Eugene's army. Their victory had no effect, because the day before the French lost the decisive
Battle of Turin (7 September 1706) and had to evacuate northern Italy. On 24 September 1706 Dillon was promoted to
lieutenant général for his action at Castiglione. Under
Marshal Tessé Dillon and his regiment participated in the successful defence of Toulon in the
Siege of Toulon (1707). In 1707 Austria signed the Convention of Milan ending the war in northern Italy. in 1708 Dillon's regiment was transferred to the
Moselle where Dillon served under
Claude Louis Hector de Villars and
James FitzJames, 1st Duke of Berwick. In 1709 Berwick, and Dillon with him, were transferred to the
Dauphiné to guard this French province against attacks from neighbouring Savoy. Dillon defended
Briançon and on 28 August 1709 defeated , a
Baltic German in Savoyard service, at the Pont de la Vachette. It was rumoured that while in
Grenoble Dillon had an affair with
Claudine Guérin de Tencin who was at that time a nun at the convent of Montfleury at Corenc near Grenoble. She managed to leave her nunnery in 1712. In 1711 Dillon was created comte Dillon in France by
Louis XIV. commander In 1712, when the French opened peace talks with the English, James Francis Edward was told to leave France. He decided to take refuge in Lorraine (not yet part of France at that time). He left Saint-Germain-en-Laye on 6 September 1712 and arrived in Lorraine in February 1713 after a short stay in
Châlons-sur-Marne. The
Peace of Utrecht on 11 April 1713 ended the war between France on one hand and Britain, the Netherlands, and Savoy on the other hand. In the treaty, France recognised the
Hanoverian Succession and formally ended its support for the Jacobites. However, the war between France and Austria continued. Comte Dillon, as he was now, was transferred from the Dauphiné to the Rhine for the
campaign of 1713, where he served under Villars capturing
Kaiserslautern on 24 June 1713 and the
Castle Wolfstein. He then participated in the siege of Landau, 24 June to 26 August 1713, under Marshall
Jacques Bazin de Bezons and in the siege of Freiburg, 20 September to 17 November 1713. The
Treaty of Rastatt on 17 March 1714 ended the war with Austria. However, the war still raged on in Spain where Catalonia tried to preserve Catalan autonomy by supporting
Charles III against
Philip V as Spanish King. Dillon was transferred to Spain under the command of Berwick where he returned to sit before Barcelona as he had done already in 1697. This
Siege of Barcelona (1713-1714) was his last campaign. The town was stormed on 11 September 1714 and capitulated on the 12. == Later life ==