Kaya Alp
Kaya Alp was, according to Ottoman tradition, the son of Kızıl Buğa and the father of Suleyman Shah, who was, in turn, the grandfather of Ertuğrul, and the great grandfather of the Ottoman Empire founder, Osman I.
Agnes II, Abbess of Quedlinburg
Agnes II( Agnes of Meissen; 1139 – 21 January 1203) was a member of the House of Wettin who reigned as Princess- Abbess of Quedlinburg.
Agnes of Waiblingen
Agnes of Waiblingen( 1072/ 73 – 24 September 1143), also known as Agnes of Germany, Agnes of Poitou and Agnes of Saarbrücken, was a member of the Salian imperial family.
Through her first marriage, she was Duchess of Swabia; through her second marriage, she was Margravine of Austria.
Elisabeth of Meissen
Elisabeth of Meissen, Burgravine of Nuremberg( 22 November 1329 – 21 April 1375) was the daughter of Frederick II, Margrave of Meissen and Mathilde of Bavaria and a member of the House of Wettin.
John I, Duke of Brunswick-Grubenhagen
John I, Duke of Brunswick- Grubenhagen( born: before 1322; died: 23 May 1367) was provost of the St. Alexandri Minster in Einbeck.
He was the son of Duke Henry I" the Marvelous" of Brunswick- Grubenhagen and his wife Agnes of Meissen, daughter of Margrave Albert II of Meissen.
Agnes of Meissen
Agnes of Meissen (born before 1264 – died after September 1332) was a noblewoman, the daughter of Albert II, Margrave of Meissen and his wife Margaret of Sicily.
Agnes was married with Henry I "the Marvelous" of Brunswick-Grubenhagen, in 1282.
They had 16 children:
Albert, Margrave of Meissen (1934–2012)
Prince Albert Joseph Maria Franz-Xaver of Saxony, Duke of Saxony, Margrave of Meissen (30 November 1934 – 6 October 2012) was the head of the Royal House of Saxony and a German historian.
The fourth child and youngest son of Friedrich Christian, Margrave of Meissen and his wife Princess Elisabeth Helene of Thurn and Taxis, he was the younger brother of Maria Emanuel, Margrave of Meissen, who was his predecessor as head of the Royal House of Saxony.
Albrecht I of Meissen
Albrecht I of Meissen( died 1 August 1152) was Bishop of Meissen from 1150 to 1152.
Margaret of Sicily
Margaret of Sicily (also called Margaret of Hohenstaufen or Margaret of Germany) (1 December 1241, in Foggia – 8 August 1270, in Frankfurt-am-Main)
was a Princess of Sicily and Germany, and a member of the House of Hohenstaufen.
By marriage she was Landgravine of Thuringia and Countess Palatine of Saxony (German: "
Landgräfin von Thüringen und Pfalzgräfin von Sachsen").
She was the daughter of Frederick II, Holy Roman Emperor, King of Sicily and Germany, by his third wife, Isabella of England.
Her paternal grandparents were Henry VI, Holy Roman Emperor and Constance of Sicily.
Her maternal grandparents were John of England and Isabella of Angoulême.
Volkold
Volkold of Meissen( also Wolcold, Folcold, Folchold, Volhold, Volkhuld, Volchrad, Vocco; d. 23 August 992) was the second Bishop of Meissen.

Question: Who is the maternal grandfather of Agnes Of Meissen?