Friedrich Ferdinand, Duke of Schleswig-Holstein
Friedrich Ferdinand of Schleswig- Holstein- Sonderburg- Glücksburg( 12 October 1855 – 21 January 1934) was the fourth Duke of Schleswig- Holstein- Sonderburg- Glücksburg and became Duke of Schleswig- Holstein in 1931.
Abel, Lord of Langeland
Abel Abelsøn( 1252 – 2 April 1279), Lord of Langeland, was the third son of King Abel of Denmark, Duke of Schleswig and younger brother of Valdemar III, Duke of Schleswig and Eric I, Duke of Schleswig.
As a member of the ducal family, he held several fiefs in Southern Denmark.
Abel, King of Denmark
Abel Valdemarsen (1218 – 29 June 1252) was Duke of Schleswig from 1232 to 1252 and King of Denmark from 1250 until his death in 1252.
He was the son of Valdemar II by his second wife, Berengaria of Portugal, and brother to Eric IV and Christopher I.
As Duke of Schleswig, Abel came into conflict with his brother, King Eric IV, whose murder in 1250 he was suspected of orchestrating.
Upon taking an oath to clear himself of the allegations, he was elected king.
After a short reign, he was killed during a military expedition in Frisia.
Abel's reign was the shortest of any Danish monarch since the 9th century.
He founded a line of Dukes of Schleswig - the "Abel family" - which ruled the Duchy of Schleswig until 1375.
Eric Longlegs, Lord of Langeland
Erik Eriksøn, also known as Eric Longlegs,( 1272 – 1310), Lord of Langeland, was the second son of Eric I, Duke of Schleswig and younger brother of Valdemar IV, Duke of Schleswig.
Eric I, Duke of Schleswig
Eric I Abelsøn  (died 27 May 1272) was a Danish nobleman.
He was the ruling Duke of Schleswig from 1260 until his death in 1272.
He was the second son of King Abel of Denmark, Duke of Schleswig and Mechtild of Holstein.
Tjuyu
Tjuyu( sometimes transliterated as Thuya or Thuyu) was an Egyptian noblewoman and the mother of queen Tiye, and the wife of Yuya.
She is the grandmother of Akhenaten, and great grandmother of Tutankhamun.
Henry, Duke of Schleswig
Henry, Duke of Schleswig( – August 1375) was Duke of Schleswig( or Southern Jutland, as the Danes call it) from 1364 until his death.
Albert, Duke of Schleswig-Holstein
Albert, Duke of Schleswig- Holstein( Albert John Charles Frederick Alfred George; 26 February 1869 – 27 April 1931), was a grandson of Queen Victoria.
He was the second son of Victoria's daughter, Princess Helena, by her husband Prince Christian of Schleswig- Holstein.
He was the head of the House of Oldenburg and also the House of Schleswig- Holstein- Sonderburg- Augustenburg and the Duke of Schleswig- Holstein between 1921 and 1931.
Wilhelm Friedrich, Duke of Schleswig-Holstein
Friedrich, Duke of Schleswig- Holstein- Sonderburg- Glücksburg, from 1934 Duke of Schleswig- Holstein( 23 August 1891 – 10 February 1965), was the Duke of Schleswig- Holstein and Head of the House of Oldenburg from 21 January 1934 until his death on 10 February 1965.
Hubba bint Hulail
Hubba bint Hulail was the grandmother of Hashim ibn' Abd Manaf, thus the great- great- great- grandmother of the Islamic" Nabī"( Prophet) Muhammad ibn Abdullah.

Question: Who is Eric I, Duke Of Schleswig's paternal grandmother?
Answer: Berengaria of Portugal