Question: Who is Catherine Of Lancaster's paternal grandfather?

Knowledge 1: Catherine of Lancaster
Catherine of Lancaster (Castilian: "Catalina"; 31 March 1373 – 2 June 1418) was Queen of Castile by marriage to King Henry III of Castile.She governed Castile as regent from 1406 until 1418 during the minority of her son.Queen Catherine was the daughter of John of Gaunt, 1st Duke of Lancaster, and his second wife, Constance of Castile (the daughter and heir of King Peter of Castile, who died at the hands of his half brother Henry II).She was born in Hertford Castle, her father's chief country home, on 31 March 1373.Catherine became Queen of Castile through her marriage to Henry III. [SEP] Knowledge 2: John of Gaunt
John of Gaunt, Duke of Lancaster (6 March 1340 – 3 February 1399) was an English prince, military leader, and statesman.He was the third of the five sons of King Edward III of England who survived to adulthood.Due to his royal origin, advantageous marriages, and some generous land grants, Gaunt was one of the richest men of his era, and an influential figure during the reigns of both his father, Edward, and his nephew, Richard II.As Duke of Lancaster, he is the founder of the royal House of Lancaster, whose members would ascend to the throne after his death.His birthplace, Ghent, corrupted into English as "Gaunt", was the origin for his name.When he became unpopular later in life, scurrilous rumours and lampoons circulated that he was actually the son of a Ghent butcher, perhaps because Edward III was not present at the birth.This story always drove him to fury.John's early career was spent in France and Spain fighting in the Hundred Years' War.He made an abortive attempt to enforce a claim to the Crown of Castile that came through his second wife, and for a time styled himself as King of Castile.As Edward the Black Prince, Gaunt's elder brother and heir to the ageing Edward III, became incapacitated due to poor health, Gaunt assumed control of many government functions, and rose to become one of the most powerful political figures in England.He was faced with military difficulties abroad and political divisions at home, and disagreements as to how to deal with these crises led to tensions between Gaunt, the English Parliament, and the ruling class, making him an extremely unpopular figure for a time.John exercised great influence over the English throne during the minority of King Richard II, and the ensuing periods of political strife.He mediated between the king and a group of rebellious nobles, which included Gaunt's own son and heir, Henry Bolingbroke.Following Gaunt's death in 1399, his estates and titles were declared forfeit to the Crown, and his son, now disinherited, was branded a traitor and exiled.Henry Bolingbroke returned from exile shortly after to reclaim his inheritance, and deposed Richard.He reigned as King Henry IV of England (1399–1413), the first of the descendants of John of Gaunt to hold the English throne.The House of Lancaster would rule England from 1399 until the time of the Wars of the Roses, when the English crown was disputed with the House of York (formed by the descendants both of his younger brother Edmund, Duke of York and his elder brother, Lionel, Duke of Clarence).Gaunt also fathered five children outside marriage: one early in life by a lady-in-waiting to his mother, the others by Katherine Swynford, his long-term mistress and third wife.They were later legitimised by royal and papal decrees, but which did not affect Henry IV's bar to their having a place in the line of succession.Gaunt is ancestor to the English monarchs of the houses of Lancaster by his first wife and Tudor by his mistress and later third wife, whose children bore the surname "Beaufort".
Knowledge 1: Catherine of Lancaster
Catherine of Lancaster (Castilian: "Catalina"; 31 March 1373 – 2 June 1418) was Queen of Castile by marriage to King Henry III of Castile.She governed Castile as regent from 1406 until 1418 during the minority of her son.Queen Catherine was the daughter of John of Gaunt, 1st Duke of Lancaster, and his second wife, Constance of Castile (the daughter and heir of King Peter of Castile, who died at the hands of his half brother Henry II).She was born in Hertford Castle, her father's chief country home, on 31 March 1373.Catherine became Queen of Castile through her marriage to Henry III. [SEP] Knowledge 2: Lyon Cohen
Lyon Cohen( 1868–1937) was a Polish- born Canadian businessman and a philanthropist.He was the grandfather of singer/ poet Leonard Cohen.
Knowledge 1: Catherine of Lancaster
Catherine of Lancaster (Castilian: "Catalina"; 31 March 1373 – 2 June 1418) was Queen of Castile by marriage to King Henry III of Castile.She governed Castile as regent from 1406 until 1418 during the minority of her son.Queen Catherine was the daughter of John of Gaunt, 1st Duke of Lancaster, and his second wife, Constance of Castile (the daughter and heir of King Peter of Castile, who died at the hands of his half brother Henry II).She was born in Hertford Castle, her father's chief country home, on 31 March 1373.Catherine became Queen of Castile through her marriage to Henry III. [SEP] Knowledge 2: 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.

Answer: Edward III of England