Editing House of Savoy-Carignano (section)

==Piedmontese Civil War==
{{main|Piedmontese Civil War}}
After seeking Spanish support late in 1638 for action against the Regent [[Christine of Savoy]], ''Madame Royale'', Thomas went to [[Milan]] early in 1639, and alongside Spanish forces invaded [[Piedmont]], where many towns welcomed him. He took Turin by knavery but the French continued to control its citadel. In 1640, he held the city in the multi-layered [[Siege of Turin (1640)|siege of Turin]]. After repeated bouts of negotiations with the Regent and the French, Thomas Francis made peace with both in the first half of 1642, unblushingly changed sides, and started fighting with the French against the Spaniards.

===Service with France===
For the rest of 1642 and part of the 1643 campaigns, Thomas Francis commanded Savoyard forces fighting alongside the French under [[Henri II d'Orléans, duc de Longueville]], against the Spanish, generally along the Piedmont–Milan border; when Longueville was recalled home, he succeeded him as allied commander-in-chief, with [[Henri de la Tour d'Auvergne, Vicomte de Turenne]], as his second-in-command. Thomas Francis was given the supreme command only because of his birth; another French general, [[César de Choiseul du Plessis Praslin]], observed a few years later that French marshals would only serve under someone who was superior to them in social rank, and Thomas Francis, with his blood relationship to the French and Spanish royal families, was the only candidate.<ref name="Du Plessis Praslin">{{cite book|title= Mémoires du maréchal de Gramont [and] Mémoires des divers emplois et des principales actions du Maréchal du Plessis (2 vols.)|series= Collection des mémoires relatifs à l'histoire de la France, vols. 56-7|date = July 1826|location=Paris|language= fr|pages= vol. 2, p.233–4|no-pp= true}}</ref>

By late summer, both Thomas Francis and Turenne were seriously ill and du Plessis Praslin was in temporary command. Thomas Francis led the joint armies again in 1644, taking Santya and [[Asti]]; he also tried to take [[Finale Ligure]] but gave up the attempt, apparently because he feared this valuable port would end up under French control rather than Savoyard. In 1645, now commanding with du Plessis Praslin, he took [[Vigevano]], and repulsed a Spanish attempt to block his withdrawal at the River Mora, the nearest he ever came to a success in the field. In 1646, Thomas Francis was put in command of the French expedition sent south to take the Tuscan [[Fortification|forts]], after which he was to advance further south to Naples, drive out the Spanish and put himself on the throne of the [[Kingdom of Naples|kingdom]]; but the expedition set off late, and when he [[Battle of Orbetello|besieged Orbetello]], the supporting French fleet was defeated by the Spanish and he was forced to raise the siege and conduct a difficult retreat, which he performed poorly.<ref name="Chéruel_1">{{cite book|last= Chéruel|first= Pierre Adolphe|title= Histoire de la France pendant la minorité de Louis XIV|url= https://archive.org/details/histoiredefranc03chgoog|year = 1879–80|location=Paris|language= fr|pages= vol. 2, p.430–1, 459|no-pp= true}}</ref> In the 1647 campaign, Thomas Francis is mentioned as commanding alongside the French general in the forces sent across north Italy to work with the Duke of Modena [[Francesco I d'Este]] who had just allied with France and opened up a 'second front' against the Spaniards in [[Duchy of Milan|Milan]], though Mazarin confessed that he had appointed Thomas only because he feared that, if left behind in Piedmont, the Prince's [[restless spirit]] would make more trouble.<ref name="Chéruel_1" />

During his absence, Regent [[Christine Marie of France|Christine]] had gained control of the fortresses granted to Thomas Francis as part of the settlement of the [[Piedmontese Civil War]] (legally, these reverted to ducal control when the Duke came of age, which under Savoyard law [[Charles Emmanuel II, Duke of Savoy|Charles Emmanuel]] did in 1648, though his mother remained in control of the government; Christine, accompanied by her son and part of the ducal army, entered [[Ivrea]] and dismissed Thomas' personal garrison; she appointed Thomas Francis instead as governor or Asti and [[Alba, Piedmont|Alba]], positions which sweetened the blow but were entirely under ducal control, not guaranteed by treaty. When he returned to Piedmont, Thomas had no choice but to accept the fait accompli, and soon after this he went to live in Paris. During the [[Fronde]], Thomas Francis linked himself closely with [[Cardinal Mazarin]] who, although effectively [[chief minister of France]], was like him an Italian outsider at the French court. In the early 1650s, Thomas Francis was seen as an important member of Mazarin's party, closely linked to the Cardinal, regularly seen in conference with him, and active in his support. In 1651 when Mazarin had been forced into exile, the Prince was for a time brought onto the ''[[conseil du roi]]'', and an admittedly very hostile contemporary [[Marie de Nemours]], the [[Duchess of Nemours]], described him as a "prime minister without being aware of it". There were suggestions that Mazarin's opponents within the court had raised him up as a rival to the cardinal with the Queen Regent [[Anne of Austria]]; this is unlikely, especially since Mazarin himself urged the Queen to follow Thomas' advice, and it is more probable that Mazarin backed the Prince as someone who would keep other rivals from gaining control in his absence but who would never have the status within France to set himself up as a permanent replacement for the Cardinal. By the time Mazarin returned from his second and last exile in February 1653, Thomas Francis, who accompanied the court to [[Saint-Denis, Seine-Saint-Denis|St Denis]] to welcome the Cardinal home, was insignificant again—an analysis of Mazarin's close colleagues at this time by the later historian [[Pierre Adolphe Chéruel]] made no mention of him.<ref name="Chéruel_2">{{cite book|last= Chéruel|first= Pierre Adolphe|title= Histoire de la France sous le ministère de Mazarin (1651-1661)|year = 1882|location=Paris|language= fr|pages= vol. 1, p.74–7, vol.2, 7–11|no-pp= true}}</ref>

In January 1654, when the last of the ceremonial offices formerly belonging to the rebel leader [[Louis II de Bourbon, Prince de Condé]], were disposed of, Prince Thomas Francis was made ''Grand Maitre''. The Franco-Spanish war had been continuing in north Italy, and late in 1654 the increasing Savoyard hostility to the current French commander Grancey led to a search for a new allied commander-in-chief; the French would have preferred to send the [[Duke of York]] (later [[King James II]]); as he was unacceptable to Turin, Thomas Francis was appointed as joint commander, akthough his wife was held in France almost as a hostage for his good behaviour. On 16 December 1654, he arrived in Turin to a ceremonial welcome by the French troops and an unexpectedly friendly reception by Duke [[Charles Emmanuel II, Duke of Savoy|Charles Emmanuel]].<ref>Theatrum Europaeum, vii, 605-6</ref> After the 1655 campaign, Thomas Francis returned to Turin where he died the following January.