Isabella, Countess of Gloucester
Isabella, Countess of Gloucester( c. 1173 – 14 October 1217), was an English noblewoman who was married to King John prior to his accession.
Mary de Monthermer
Mary MacDuff, Countess of Fife ("née" de Monthermer; October 1297 – circa 1371) was an English noblewoman.
She was a daughter of Ralph de Monthermer, 1st Baron Monthermer and his wife Joan of Acre.
Other sources have her being born in 1298.
William Comyn of Kirkintilloch
William Comyn of Kirkintilloch( died 1291) was a 13th- century Scottish nobleman.
He was a son of John Comyn, Lord of Badenoch( died c. 1275) and Alicia de Ros. William was married to Isabella Russell, daughter of Isabella, Countess of Menteith and John Russell.
Petitions were placed to King Edward I of England and King Alexander III of Scotland claiming the Earldom of Mentieth, in the right of Isabella, his wife and in 1285 half the lands of the Earldom of Mentieth were granted to William and Isabella.
The title of the Earl of Mentieth was kept by Walter Bailloch, jure uxoris by his wife Mary, sister of Isabella, Countess of Menteith.
William died in 1291, without issue by his own wife.
Isabella, Countess of Fife
Isabella MacDuff, Countess of Fife (c. 1320–1389) was a Scottish noblewoman who was Countess of Fife from 1363 until she resigned the title in 1371.
She was the only child of Duncan, Earl of Fife, by his wife Mary de Monthermer, daughter of Ralph, Lord Monthermer and Joan of Acre.
In 1332 she and her mother had been captured at Perth by supporters of Edward Balliol.
She was sent as a ward to Northumberland.
Her first husband was Sir William Ramsay of Colluthie in Fife, whom she married around 1358.
He died soon afterwards, leaving a son, but by an earlier marriage.
She was next married, before June 1361, to Walter Stewart, second son of Robert Stewart, later King Robert II.
He died without issue the following year, and she was married again in January 1363 to Sir Thomas Bisset of Upsetlington in Berwickshire.
He had died by April 1366.
She was married for a fourth and final time to John Dunbar, who died before 1371.
She had no children by any of her marriages.
Isabel was persuaded to resign the earldom on 30 March 1371 to Robert Stewart, Earl of Menteith
(later Duke of Albany), who was her brother-in-law by her second marriage.
She died shortly after 12 August 1389 and was buried next to Walter Stewart.
Causantín, Earl of Fife
Causantín or Constantine of Fife( floruit 1095 – 1128) is the first man known for certain to have been Mormaer of Fife.
Lyon Cohen
Lyon Cohen( 1868–1937) was a Polish- born Canadian businessman and a philanthropist.
He was the grandfather of singer/ poet Leonard Cohen.
Walter Stewart, Lord of Fife
Walter Stewart( c.1338–1362) was the second son of Robert Stewart, 7th High Steward of Scotland( afterwards King Robert II) and Elizabeth Mure.
He married Isabella, Countess of Fife between 21 July 1360 and 20 July 1361 and was styled Lord of Fife—he died in late 1362.
Molly Costain Haycraft
Molly Costain Haycraft (6 December 1911 – 5 June 2005) was a Canadian author.
She was born in Toronto, Ontario, Canada, and spent her childhood in Philadelphia, where her father, the well-known novelist Thomas B. Costain, was an editor for "The Saturday Evening Post".
She was the author of several novels about women in English royal history.
These include "The Lady Royal,The Reluctant Queen," and "Too Near the Throne.
The Lady Royal" centres on the life of Isabella, Countess of Bedford, during the Hundred Years War.
She died in Hightstown, NJ, in 2005
Abd al-Muttalib
Abd al- Muttalib Shaybah ibn Hashim( c. 497 – 578) was the grandfather of Islamic prophet Muhammad.
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.

Question: Who is the maternal grandfather of Isabella, Countess Of Fife?
Answer: Ralph de Monthermer