Autograph letter signed ("La Comtesse de Soissons").
Small 4to. 1 p. on bifolium with integral address panel.
To the Marquis de St Thomas, affirming her eternal closeness and gratitude for his efforts on behalf of her children.
Olympia (Olympe) was the second eldest of the five celebrated Mancini sisters, who, along with two of their female Martinozzi cousins, were known at the court of King Louis XIV of France as the "Mazarinettes" because their uncle was Louis XIV's chief minister, Cardinal Mazarin. Olympia was also the mother of the famous Austrian general Prince Eugene of Savoy.
Somewhat wrinkled and spotty; insignificant torn-out portion on fol. 2 due to breaking of seal. From the autograph collection of the famous Swiss-Italian editor Ulrico Hoepli (1847-1935); a facsimile print of the letter's second part was published in Autografi dal Secolo XV al XIX. dalla Racolta Hoepli (plate 17, no. 81).