As is widely known, Edward II's parents were Edward I, born 1239, King of England 1272 to 1307, and Eleanor, the Infanta Leonor de Castilla, probably born in 1241, died 1290. Eleanor was the twelfth of her father's fifteen children, and succeeded her mother as Countess of Ponthieu and Montreuil, though she never used the title in England.
Edward's grandparents were:
Henry III, King of England, born 1207, reigned 1216 to 1272. Crowned at the age of nine, Henry reigned for fifty-six years, one of the longest reigns in British history. In many ways, his reign foreshadows that of Edward II; Henry advanced his 'favourites' (actually his half-siblings and his wife's relatives) and was involved in long-running conflicts with his barons, led by his brother-in-law Simon de Montfort, earl of Leicester. Henry was even imprisoned for a time, though he never suffered his grandson's fate of deposition. On the plus side, Henry is remembered for his ambitious re-building programme at Westminster Abbey, Windsor Castle, etc, and was a devoted husband and father.
Eleanor (or Eleonore or Alianore, etc) of Provence, Queen of England, c. 1223 to 1291. Married to Henry III in January 1236, when he was twenty-eight and she was probably twelve or thirteen. Eleanor was the second of four sisters, who all became queens. They were: Marguerite, who married Louis IX of France; Sancha, married to Henry III's brother Richard of Cornwall, who became King of the Romans in 1257; and Beatrice, the wife of Louis IX's brother Charles of Anjou, King of Sicily. She and Henry had two sons and three daughters; Eleanor outlived all three daughters. She retired to Amesbury Priory in 1285.
Fernando III, King of Castile and Leon, 'the Saint', 1199/1201 to 1252. He fought against the Moors as part of the Spanish Reconquista, capturing Cordoba, Jaen and Seville. He was first married to Elisabeth of Swabia, who was known as Beatriz in Spain; she bore him ten children, including his heir Alfonso X, 'the Wise'.
Jeanne de Dammartin, Queen of Castile and Countess of Ponthieu in her own right, 1216/20 to 1279. She was betrothed to Henry III of England, but Blanche of Castile, mother of Louis IX and Regent of France, opposed the match, and it never took place. Instead, Blanche proposed a match with her widowed nephew Fernando III for the heiress, and they married in 1237. Jeanne returned to Ponthieu after she was widowed in 1252, and lived till 1279.
Edward II's great-grandparents were:
John, King of England, born 1166
Isabelle, Queen of England and Countess of Angoulême in her own right, born c. 1187/88
Ramon-Berenger IV, Count of Provence, born c. 1195/98
Beatrice, Countess of Provence, daughter of Count Thomas I of Savoy, born c. 1198/1205
Simon de Dammartin, Count of Aumale, born c. 1180
Marie, Countess of Ponthieu in her own right, born 1199
Berenguela the Great, Queen of Castile in her own right, born 1180
Alfonso IX, King of Leon, born 1171
Only one of the eight (King John) was born in England; of his sixteen great-great-grandparents, not a single one was born in England. They included: King Henry II of England (who was born in Le Mans); Eleanor, duchess of Aquitaine, queen of France then queen of England; Alix (or Alais or Alys or Adele, etc), daughter of Louis VII, who was betrothed to Richard I of England and repudiated by him as she was allegedly his father Henry II's mistress; King Fernando II of Leon; King Alfonso VIII of Castile; and Eleanor, queen of Castile, daughter of Henry II and Eleanor of Aquitaine (she was born in Normandy, not England).
Edward II himself was born in Caernarfon, Wales, though he lived practically his whole life in England. However, his ancestry was only minimally English!