It occurred to me recently how many of the English earls of Edward II's era had a non-English mother, and in a couple of cases, a non-English father. Edward II himself was the son of a half-Spanish, half-French mother, Leonor or Eleanor of Castile. His maternal grandfather Fernando III of Castile and Leon was Spanish, and both of his grandmothers, Joan of Ponthieu (often called Jeanne de Dammartin) and Eleanor of Provence, queens of Castile and England, were French. Of Edward's eight great-grandparents, only one, King John, was born in England, two were born in Spain, and five were born in France. Of his sixteen great-great-grandparents, thirteen were born in France, two in Spain and one in Portugal, and none were born in England.
The mother of Edward II's half-brothers Thomas of Brotherton, earl of Norfolk (1300-38) and Edmund of Woodstock, earl of Kent (1301-30), was French: Marguerite of France, daughter of Philip III from his second marriage to Marie of Brabant, and half-sister of Philip IV.
The mother of Thomas (c. 1277/78-1322) and Henry (c. 1280/81-1345) of Lancaster, earls of Lancaster and Leicester, was French: Blanche of Artois, daughter of Robert, count of Artois; niece of Louis IX; widow of Enrique I of Navarre; mother-in-law of Philip IV; and grandmother of Louis X, Philip V and Charles IV of France and of Edward II's queen Isabella.
The mother of Henry de Lacy, earl of Lincoln (c. 1250-1311), was Italian: Alesia di Saluzzo, daughter of Manfredi, count of Saluzzo.
The mother of Edmund Fitzalan, earl of Arundel (1285-1326), was Italian: Alesia di Saluzzo the younger, niece of Henry de Lacy's mother of the same name, and daughter of Tommaso, count of Saluzzo.
The father of John of Brittany, earl of Richmond (c. 1266-1334) was, unsurprisingly, Breton: John II, duke of Brittany (1239-1305). John of Brittany's mother was Edward I's sister Beatrice (1242-75), making him Edward II's first cousin, and his older brother Arthur II (1262-1312) succeeded their father as duke of Brittany.
The father of Aymer de Valence, earl of Pembroke (1270s or early 1280s-1324) was French: William or Guillaume de Valence, earl of Pembroke (d. 1296). He was one of Henry III's Lusignan half-siblings, children of Hugues de Lusignan, count of La Marche, and King John's widow Isabelle of Angoulême.
The mother of Humphrey de Bohun, earl of Hereford and Essex (c. 1276-1322) was French: Maud de Fiennes, daughter of Enguerrand, seigneur de Fiennes, and Isabelle de Condé. Humphrey married Edward II's sister Elizabeth of Rhuddlan (1282-1316).
The mother of Roger Mortimer, earl of March (1286/87-1330) was French: Marguerite de Fiennes, niece of Maud de Fiennes above, and daughter of Guillaume de Fiennes and Blanche de Brienne. When Marguerite died not long before 21 February 1334, incidentally, her heir was her great-grandson Roger Mortimer the younger, born November 1328 and later the second earl of March; she had outlived her son Roger, executed in November 1330, and Roger's eldest son Edmund, who died before 21 January 1332. [Calendar of Inquisitions Post Mortem 1327-36, nos. 387, 577] Marguerite's sister Jeanne de Fiennes (d. 1309) married John, Lord Wake (d. 1300) and was the mother of Margaret Wake, countess of Kent (d. 1349) and the grandmother of Joan of Kent, princess of Wales and Aquitaine (d. 1385), Richard II's mother.
Piers Gaveston, earl of Cornwall (1270s or early 1280s-1312), was of Gascon birth and heritage, and as Gascony was then ruled by the kings of England, was a subject of the English crown and not strictly French by the standards of the time. Piers' family name derives from Gabaston, now a commune in the Pyrénées-Atlantiques department in the far south-west of France. He was the son of Arnaud de Gabaston/Gaveston and Claramonde de Marsan, and his grandfathers were Garsie de Gabaston and Arnaud-Guilhem de Marsan.
For the sake of completeness, the earl of Chester in Edward II's reign was his son Edward of Windsor, later Edward III (1312-77), whose mother was also, obviously, French: Isabella of France, daughter of Philip IV of France and Jeanne/Juana I, queen of Navarre.
John de Warenne, earl of Surrey and Sussex (1286-1347), son of William de Warenne (d. 1286) and Joan de Vere, daughter of the earl of Oxford; grandson and heir of John de Warenne, earl of Surrey and Sussex (1231-1304) and Alice de Lusignan, half-sister of Henry III and full sister of Guillaume de Valence.
Guy Beauchamp, earl of Warwick (c. 1272/75-1315), son of William Beauchamp, earl of Warwick (d. 1298) and Maud FitzJohn (d. 1301).
Hugh Despenser the Elder, earl of Winchester (1261-1326), son of Hugh Despenser, justiciar of England (d. 1265) and Aline Basset, countess of Norfolk (d. 1281).
Andrew Harclay, earl of Carlisle (c. 1270-1323), probably the eldest son of Sir Michael Harclay and Joan FitzJohn.
Robert de Vere, earl of Oxford (1257-1331), was the son of Robert de Vere, earl of Oxford (d. 1296) and Alice Sanford, and was the maternal uncle of John de Warenne (1286-1347).