Question: Who is the paternal grandfather of Princess Catherine Of Schleswig-Holstein-Sonderburg-Beck?

Knowledge 1: Princess Catherine of Schleswig-Holstein-Sonderburg-Beck
Princess Catherine of Schleswig-Holstein-Sonderburg-Beck (23 February 1750 – 20 December 1811) was the member of the House of Schleswig-Holstein-Sonderburg-Beck.She was a daughter of Duke Peter August of Holstein-Beck, who was a Russian field marshal and Governor of Estonia, and his second wife, Countess Natalia Golovina.On 8 January 1767 in Revel, she married Prince , the Russian ambassador in France.Their children were: Ivan Ivanovitch, 20th Prince Bariatinski (1772-1825) and Princess Anna Ivanovna Bariatinskaia (1774-1825).Through their son, they are the 5th great-grandparents of Franca Sozzani.Aleksandr Baryatinsky, the Russian Field Marshal, was her grandson.By the early 1770s, the couple had been separated.On 29 March 1800, she purchased Friedrichfelde Castle in Berlin from the printer and publisher Georg Jacob Decker the Younger.With permission from the King, she reverted to her maiden name, and as Duchess Catherine of Holstein-Beck, she led a lavish life, with close ties to the royal family.Besides Friedrichfelde Castle, she owned a town house on Pariser Platz. [SEP] Knowledge 2: Peter August, Duke of Schleswig-Holstein-Sonderburg-Beck
Peter August Friedrich, Duke of Schleswig-Holstein-Sonderburg-Beck (7 December 1697 – 22 March 1775) was a Duke of Schleswig-Holstein-Sonderburg-Beck.He was the fifth and youngest son of Frederick Louis, Duke of Schleswig-Holstein-Sonderburg-Beck and his wife Duchess Louise Charlotte of Schleswig-Holstein-Sonderburg-Augustenburg.Born in Königsberg, Brandenburg-Prussia, Peter August became Governor General of Reval (Tallinn), Governor of Estonia, and a Field Marshal in the Russian Imperial Army.He died in Reval.He was only the "titular" duke, because he did not inherit the domain of Beck.It had been inherited by his father's older brother, Duke August (1652–1689), and nephew Frederick William I (1682–1719), and was then sold by the latter's widow to Peter August's older brother, Duke Frederick William II (1687–1749), in 1732.But he re-sold it in 1745 to Baroness Magdalena von Ledebur-Königsbrück.Thus, by the time that Peter August became the head of this cadet branch of the Danish royal dynasty, he was "Duke of Schleswig-Holstein-Sonderburg-Beck" in name only.He is the male line ancestor of Margrethe II of Denmark, Harald V of Norway and Charles, Prince of Wales.
Knowledge 1: Princess Catherine of Schleswig-Holstein-Sonderburg-Beck
Princess Catherine of Schleswig-Holstein-Sonderburg-Beck (23 February 1750 – 20 December 1811) was the member of the House of Schleswig-Holstein-Sonderburg-Beck.She was a daughter of Duke Peter August of Holstein-Beck, who was a Russian field marshal and Governor of Estonia, and his second wife, Countess Natalia Golovina.On 8 January 1767 in Revel, she married Prince , the Russian ambassador in France.Their children were: Ivan Ivanovitch, 20th Prince Bariatinski (1772-1825) and Princess Anna Ivanovna Bariatinskaia (1774-1825).Through their son, they are the 5th great-grandparents of Franca Sozzani.Aleksandr Baryatinsky, the Russian Field Marshal, was her grandson.By the early 1770s, the couple had been separated.On 29 March 1800, she purchased Friedrichfelde Castle in Berlin from the printer and publisher Georg Jacob Decker the Younger.With permission from the King, she reverted to her maiden name, and as Duchess Catherine of Holstein-Beck, she led a lavish life, with close ties to the royal family.Besides Friedrichfelde Castle, she owned a town house on Pariser Platz. [SEP] Knowledge 2: August, Duke of Schleswig-Holstein-Sonderburg-Beck
August, Duke of Schleswig- Holstein- Sonderburg- Beck( 13 February 1652 – 26 September 1689 in Bonn) was a German nobleman.From 1675 until his death, he was the ruling Duke of Schleswig- Holstein- Sonderburg- Beck.He was the second duke of this appanage.
Knowledge 1: Princess Catherine of Schleswig-Holstein-Sonderburg-Beck
Princess Catherine of Schleswig-Holstein-Sonderburg-Beck (23 February 1750 – 20 December 1811) was the member of the House of Schleswig-Holstein-Sonderburg-Beck.She was a daughter of Duke Peter August of Holstein-Beck, who was a Russian field marshal and Governor of Estonia, and his second wife, Countess Natalia Golovina.On 8 January 1767 in Revel, she married Prince , the Russian ambassador in France.Their children were: Ivan Ivanovitch, 20th Prince Bariatinski (1772-1825) and Princess Anna Ivanovna Bariatinskaia (1774-1825).Through their son, they are the 5th great-grandparents of Franca Sozzani.Aleksandr Baryatinsky, the Russian Field Marshal, was her grandson.By the early 1770s, the couple had been separated.On 29 March 1800, she purchased Friedrichfelde Castle in Berlin from the printer and publisher Georg Jacob Decker the Younger.With permission from the King, she reverted to her maiden name, and as Duchess Catherine of Holstein-Beck, she led a lavish life, with close ties to the royal family.Besides Friedrichfelde Castle, she owned a town house on Pariser Platz. [SEP] Knowledge 2: Friedrich Wilhelm, Duke of Schleswig-Holstein-Sonderburg-Glücksburg
Friedrich Wilhelm, Duke of Schleswig-Holstein-Sonderburg-Glücksburg (4 January 1785 – 17 February 1831) inherited the title of Duke of Schleswig-Holstein-Sonderburg-Beck in 1816.He subsequently changed his title to Duke of Schleswig-Holstein-Sonderburg-Glücksburg in 1825 and founded a line that includes the Royal Houses of Denmark, Greece, Norway, and the Commonwealth realms.

Answer: Frederick Louis