Question: Who is the maternal grandfather of Hedda Von Fersen?

Knowledge 1: Hedda von Fersen
Hedvig "Hedda" Eleonora von Fersen (2 July 1753 – 8 November 1792, Pisa) was a Swedish noble, lady in waiting to the Swedish queen, Sophia Magdalena of Denmark.She was the daughter of Axel von Fersen the Elder and Hedvig Catharina De la Gardie and the sister of Count Axel von Fersen the Younger, Sophie Piper and Fabian von Fersen (1762–1818).In 1773, she married marshal Count Thure Leonard Klinckowström in his second marriage, and with him had four children, among them the artist Hedvig Amalia Charlotta Klinckowström and Axel Leonhard Klinckowström, member of the Royal Swedish Academy of War Sciences and la Société pour l'encouragement de l'industrie nationale. [SEP] Knowledge 2: Hedvig Catharina von Fersen
Hedvig Catharina von Fersen, née De la Gardie (Stockholm, 20 May 1732–Stockholm, 24 April 1800) was a Swedish noble.She was the daughter of the General and "riksråd" count Magnus Julius De la Gardie and the political salonist Hedvig Catharina Lilje, and sister of scientist Eva Ekeblad.
Knowledge 1: Hedda von Fersen
Hedvig "Hedda" Eleonora von Fersen (2 July 1753 – 8 November 1792, Pisa) was a Swedish noble, lady in waiting to the Swedish queen, Sophia Magdalena of Denmark.She was the daughter of Axel von Fersen the Elder and Hedvig Catharina De la Gardie and the sister of Count Axel von Fersen the Younger, Sophie Piper and Fabian von Fersen (1762–1818).In 1773, she married marshal Count Thure Leonard Klinckowström in his second marriage, and with him had four children, among them the artist Hedvig Amalia Charlotta Klinckowström and Axel Leonhard Klinckowström, member of the Royal Swedish Academy of War Sciences and la Société pour l'encouragement de l'industrie nationale. [SEP] Knowledge 2: Louise von Fersen
Lovisa Sofia Louise" Sophie" von Fersen, née Piper (26 October 1777 – 4 January 1849), was a Swedish countess and courtier.Louise von Fersen was the daughter of court chamberlain Sten Abraham Piper and Catharina Ehrensvärd, who had been "hovfröken" (maid of honour) prior to her marriage.She served as maid of honour to princess Sophia Albertina of Sweden in 1794-97.She married the courtier count Fabian Reinhold von Fersen in 1797.By marriage, she became the sister-in-law to the famous Axel von Fersen the Younger as well as Sophie Piper, who was married to her brother Carl Piper.Their children: Axel von Fersen (1798–1839), Fabian von Fersen (1800-1800), Gustaf Hans von Fersen (1802-1839) and the great heiress Louise von Fersen (1816–1879), of whom all sons died officially childless (although Gustaf Hans had in fact several children with Carolina Brunström), were the last of the von Fersen family.She served as "hovmästarinna" (deputy mistress of the robes) in 1804-05 and "överhovmästarinna" (Mistress of the Robes) in 1805-09 to queen Frederica, and Mistress of the Robes to queen Charlotte in 1809-10.Count Hans Gabriel Trolle-Wachtmeister said of her that she "was the most beautiful Juno-like figure you could see  undoubtedly the most accomplished woman in high society".
Knowledge 1: Hedda von Fersen
Hedvig "Hedda" Eleonora von Fersen (2 July 1753 – 8 November 1792, Pisa) was a Swedish noble, lady in waiting to the Swedish queen, Sophia Magdalena of Denmark.She was the daughter of Axel von Fersen the Elder and Hedvig Catharina De la Gardie and the sister of Count Axel von Fersen the Younger, Sophie Piper and Fabian von Fersen (1762–1818).In 1773, she married marshal Count Thure Leonard Klinckowström in his second marriage, and with him had four children, among them the artist Hedvig Amalia Charlotta Klinckowström and Axel Leonhard Klinckowström, member of the Royal Swedish Academy of War Sciences and la Société pour l'encouragement de l'industrie nationale. [SEP] Knowledge 2: Sophie Piper
Eva Sophie Piper, née Eva Sophie von Fersen( 30 March 1757 – 2 February 1816, Löfstad Slott), was a Swedish countess and lady in waiting.She was the daughter of count Axel von Fersen the Elder and Hedvig Catharina von Fersen and the sister of Axel von Fersen the Younger, Hedvig Eleonora von Fersen and Fabian von Fersen( 1762 – 1818).She is foremost known for her close friendship with Queen Hedvig Elizabeth Charlotte, who dedicated her famous diary to her.

Answer: Magnus Julius De la Gardie