She was a niece of the vicomte de Turenne.
His talents were perceived by Turenne in the War of Devolution (1667–68), who gave him instruction in the art of providing armies.
In the following year Mercy opposed the French armies, now under the Great Condé and the Vicomte de Turenne.
In 1673, when he was aged 24, he entered the French Army of Louis XIV and served under the famous Marshal de Turenne before returning to Scotland sometime around 1675.
However, he could not prevent Turenne from advancing across the Rhine.
Between 1652 and 1655 Berkeley served under Turenne in the campaigns against Condé, and the Spaniards in Flanders, accompanying the Duke of York as a volunteer.
John Christian was married with Marie Anne Henriëtte Leopoldine de La Tour d'Auvergne, marquise of Bergen op Zoom and a grandniece of Henri de la Tour d'Auvergne, Vicomte de Turenne.
He was also made a colonel of infantry, and served for some time under Turenne.
#Marie Anne (1649–1714) married Maurice Godefroy de la Tour d'Auvergne, Duke of Bouillon, nephew of Turenne.
In 1673 he was with Monmouth at Maastricht and was present during two campaigns with Turenne on the Rhine.
Six marshals of France have been given the even more exalted rank of "marshal general of France" (maréchal général de France): Biron, Lesdiguières, Turenne, Villars, Saxe and Soult.
Whether named to honour the French military hero Marshal Turenne or related to the earlier word terrine, a borrowing from the French for 'a large, circular, earthenware dish'.
Henri de la Tour d'Auvergne, Vicomte de Turenne | Turenne | Vaux-le-Vicomte | Louis Turenne | La Chaize-le-Vicomte | Turenne, Corrèze | vicomte | The Vicomte of Bragelonne: Ten Years Later | Vicomte de Turenne | vicomte de Turenne | Vicomte d'Archiac | Théodore Claude Henri, vicomte Hersart de la Villemarqué | Saint-Sauveur-le-Vicomte | Princess of Turenne | Henri de La Tour d'Auvergne, vicomte de Turenne, duc de Bouillon | Charles-Victor Prévot, vicomte d'Arlincourt |