Question: Who is Alexander Of Islay, Earl Of Ross's paternal grandfather?

Knowledge 1: Alexander of Islay, Earl of Ross
Alexander of Islay or Alexander MacDonald (died 1449) was a medieval Scottish nobleman, who succeeded his father Domhnall of Islay as Lord of the Isles (1423–1449) and rose to the rank of Earl of Ross (1437–49).His lively career, especially before he attained the earldom of Ross, led Hugh MacDonald, the 17th century author of "History of the MacDonalds", to commemorate him as "a man born to much trouble all his lifetime".Alexander allied himself with King James I of Scotland against the power of the
Albany Stewarts in 1425 but, once the Albany Stewarts were out of the way, Alexander quickly found himself at odds with the new king.War with King James would initially prove Alexander's undoing, and would see the King's power in Scotland greatly increased, but at the Battle of Inverlochy Alexander's army prevailed against the forces of the King.Alexander died in 1449, having greatly extended his family's landed wealth and power.He was buried, not in the Isles of his ancestors, but at Fortrose Cathedral in his mainland Earldom of Ross. [SEP] Knowledge 2: Donald of Islay, Lord of the Isles
Donald, Lord of the Isles(Gaelic: "Dómhnall"; died 1423), was the son and successor of John of Islay, Lord of the Isles and chief of Clan Donald.The Lordship of the Isles was based in and around the Scottish west-coast island of Islay, but under Donald's father had come to include many of the other islands off the west coast of Scotland, as well as Morvern, Garmoran, Lochaber, Kintyre and Knapdale on the mainland.Donald was the grandson of King Robert II of Scotland and first cousin of King Robert III; he took pride in his royal blood, even adopting the royal tressure to surround his coat of arms.While it is customary to portray the Lords of the Isles as divorced from the mainstream of Scottish political life, and as representatives of a brand of lordship distinct from the rest of Scotland, this view obscures the fact that Donald was only one of many magnates who held large lordships with little interference from the crown in late 14th and early 15th century Scotland.The Douglas kindred of southern Scotland and the Albany Stewarts had similar roles as Donald.
Knowledge 1: Donald of Islay, Lord of the Isles
Donald, Lord of the Isles(Gaelic: "Dómhnall"; died 1423), was the son and successor of John of Islay, Lord of the Isles and chief of Clan Donald.The Lordship of the Isles was based in and around the Scottish west-coast island of Islay, but under Donald's father had come to include many of the other islands off the west coast of Scotland, as well as Morvern, Garmoran, Lochaber, Kintyre and Knapdale on the mainland.Donald was the grandson of King Robert II of Scotland and first cousin of King Robert III; he took pride in his royal blood, even adopting the royal tressure to surround his coat of arms.While it is customary to portray the Lords of the Isles as divorced from the mainstream of Scottish political life, and as representatives of a brand of lordship distinct from the rest of Scotland, this view obscures the fact that Donald was only one of many magnates who held large lordships with little interference from the crown in late 14th and early 15th century Scotland.The Douglas kindred of southern Scotland and the Albany Stewarts had similar roles as Donald. [SEP] Knowledge 2: John de Moravia, 8th Earl of Sutherland
John de Moravia (also known as John Sutherland) (d. 1508) was the 8th Earl of Sutherland and chief of Clan Sutherland.During his chieftaincy his clan fought against the Clan Donald at the Battle of Skibo and Strathfleet.John de Moravia, 8th Earl of Sutherland married firstly a daughter of John of Islay, Earl of Ross and Lord of the Isles and had the following children:
John de Moravia, 8th Earl of Sutherland married secondly a daughter of the chief of the Clan Ross of Balnagown Castle and had the following two sons:
Knowledge 1: Alexander of Islay, Earl of Ross
Alexander of Islay or Alexander MacDonald (died 1449) was a medieval Scottish nobleman, who succeeded his father Domhnall of Islay as Lord of the Isles (1423–1449) and rose to the rank of Earl of Ross (1437–49).His lively career, especially before he attained the earldom of Ross, led Hugh MacDonald, the 17th century author of "History of the MacDonalds", to commemorate him as "a man born to much trouble all his lifetime".Alexander allied himself with King James I of Scotland against the power of the
Albany Stewarts in 1425 but, once the Albany Stewarts were out of the way, Alexander quickly found himself at odds with the new king.War with King James would initially prove Alexander's undoing, and would see the King's power in Scotland greatly increased, but at the Battle of Inverlochy Alexander's army prevailed against the forces of the King.Alexander died in 1449, having greatly extended his family's landed wealth and power.He was buried, not in the Isles of his ancestors, but at Fortrose Cathedral in his mainland Earldom of Ross. [SEP] Knowledge 2: John de Moravia, 8th Earl of Sutherland
John de Moravia (also known as John Sutherland) (d. 1508) was the 8th Earl of Sutherland and chief of Clan Sutherland.During his chieftaincy his clan fought against the Clan Donald at the Battle of Skibo and Strathfleet.John de Moravia, 8th Earl of Sutherland married firstly a daughter of John of Islay, Earl of Ross and Lord of the Isles and had the following children:
John de Moravia, 8th Earl of Sutherland married secondly a daughter of the chief of the Clan Ross of Balnagown Castle and had the following two sons:

Answer: John of Islay