Baldwin de Redvers, 7th Earl of Devon
Baldwin de Redvers, 7th Earl of Devon( 1 January 1236 – 1262), feudal baron of Plympton in Devon and Lord of the Isle of Wight, was the son of Baldwin de Redvers, 6th Earl of Devon and Amice de Clare, daughter of Gilbert de Clare, 5th Earl of Hertford.
He succeeded his father at the age of ten.
He died in the expedition of Henry III of England to France in 1262; the record of his death by the royal clerks was made on 13 September.
He was succeeded by his sister, Isabella de Fortibus, widow of William de Forz, 4th Earl of Albemarle.
Isabella of Gloucester and Hertford
Isabella de Clare( 2 November 1226 – 10 July 1264) was the daughter of Gilbert de Clare, 4th Earl of Hertford and 5th Earl of Gloucester and Isabel Marshal.
She is also known as" Isabel de Clare", but this is however, the name of many women in her family.
Maud de Lacy, Countess of Hertford and Gloucester
Maud de Lacy,( 25 January 1223 – 10 March 1289), was an English noblewoman, being the eldest child of John de Lacy, 2nd Earl of Lincoln, and the wife of Richard de Clare, 5th Earl of Hertford, 6th Earl of Gloucester.
Eleanor de Clare
Eleanor de Clare, suo jure 6th Lady of Glamorgan( 3 October 1292- 30 June 1337) was a powerful English noblewoman who married Hugh Despenser the Younger and was a granddaughter of Edward I of England.
With her sisters, Elizabeth de Clare and Margaret de Clare, she inherited her father's estates after the death of her brother, Gilbert de Clare, 8th Earl of Gloucester, 7th Earl of Hereford at the Battle of Bannockburn in 1314.
She was born in 1292 at Caerphilly Castle in Glamorgan, Wales and was the eldest daughter of Gilbert de Clare, 6th Earl of Hertford, 7th Earl of Gloucester, 5th Lord of Glamorgan and Princess Joan of Acre.
Bogo de Clare
Bogo de Clare (21 July 1248 – October 1294) was a member of the Anglo-Norman de Clare family, as third son of Richard de Clare (1222–1262), 5th Earl of Hertford and 6th Earl of Gloucester.
Margaret de Clare
Margaret de Clare, Countess of Gloucester, Countess of Cornwall( 12 October 1293 – 9 April 1342) was an English noblewoman, heiress, and the second- eldest of the three daughters of Gilbert de Clare, 6th Earl of Hertford and his wife Joan of Acre, making her a granddaughter of King Edward I of England.
Her two husbands were Piers Gaveston and Hugh de Audley, 1st Earl of Gloucester.
Richard de Clare, 3rd Earl of Hertford
Richard de Clare, 3rd Earl of Hertford, lord of Clare, Tonbridge, and Cardigan (–1217), was a powerful Norman nobleman with vast lands in England and Wales.
Richard de Clare, 6th Earl of Gloucester
Richard de Clare, 5th Earl of Hertford, 6th Earl of Gloucester, 2nd Lord of Glamorgan, 8th Lord of Clare( 4 August 1222 – 14 July 1262) was son of Gilbert de Clare, 4th Earl of Hertford and Isabel Marshal.
He was also a powerful Marcher Lord in Wales and inherited the Lordship of Glamorgan upon the death of his father.
He played a prominent role in the constitutional crisis of 1258 – 1263.
Gilbert de Clare, 5th Earl of Gloucester
Gilbert de Clare, 4th Earl of Hertford, 5th Earl of Gloucester, 1st Lord of Glamorgan, 7th Lord of Clare (1180 – 25 October 1230) was the son of Richard de Clare, 3rd Earl of Hertford (c. 1153–1217), from whom he inherited the Clare estates.
He also inherited from his mother, Amice Fitz William, the estates of Gloucester and the honour of St. Hilary, and from Rohese, an ancestor, the moiety of the Giffard estates.
In June 1202, he was entrusted with the lands of Harfleur and Montrevillers.
Isabel Marshal
Isabel Marshal (9 October 1200 – 17 January 1240) was a medieval English countess.
She was the wife of both Gilbert de Clare, 4th Earl of Hertford and 5th Earl of Gloucester and Richard, 1st Earl of Cornwall (son of King John of England).
With the former, she was a great grandmother of King Robert the Bruce of Scotland.

Question: Which country Gilbert De Clare, 5Th Earl Of Gloucester's father is from?
Answer: England