In Louis XV's army the classification of 'French' infantry denoted troops recruited from men born and raised in France. These regiments were called, naturally enough, infanterie francaise as opposed to the mercenary 'foreign' infantry recruited elsewhere. Making up the bulk of the army, all officers and men were to be of the Roman Catholic faith, the official state religion. Regimental recruiting parties went to towns and villages looking for likely young volunteers, inducing them to enlist with the usual promises – quick money, fast women, good wines and great glory.
Just a painting guide. Granted, a fine painting guide, but it tells you nothing about how this army fought, which would be fine if Osprey got off their asses and published a book on Fontenoy or Minden!