Free Britain's Royal Families: The Complete Genealogy by Alison Weir Page B

Reading Abbey, Berkshire.
(ii)
Isabella
She was born on 9 September, 1233, at Marlowe-on-Thames, Bucks., and died on 10 October, 1234, at Marlowe-on-Thames, Bucks.; she was buried in Reading Abbey, Berkshire.
(iii)
Henry
He was born on 2, 4 or 12 November, 1235, at Haughley Castle, Suffolk. He was murdered by the sons of Simon de Montfort on 13 March, 1271, either in the Church of St Lorenzo, or the Church of St Silvestro, or the Cathedral of St Nicholas, Viterbo, Italy, and was buried in Hayles Abbey, Gloucs.
Henry married, on 5 or 15 May, 1269, at Windsor Castle:
Constance
She was the daughter of Gaston VII de Moncada, Viscount of Beam, by Matilda, daughter of Boson de Mastas, Seigneur of Cognac. She married firstly Alfonso, Infante of Aragon ( d .1260). Constance died in c .1299.
(iv)
Nicholas
He was born on 17 January, 1240, at Berkhamstead Castle, Bucks., and died there the same day. He was buried in Beaulieu Abbey, Hampshire.
    Richard married secondly, on 23 November, 1243, at Westminster Abbey:
    Sanchia
    She was the daughter of Raymond Berenger V, Count of Provence, by Beatrice, daughter of Thomas I, Count of Savoy; her sister Eleanor was the wife of Henry III. Sanchia was born in c. 1225 at Aix-en-Provence, France. She was crowned Queen of the Romans and Queen of Germany with her husband on 17 May, 1257, at Aachen Cathedral, Germany. She died on 5 or 9 November, 1261, at Berkhamstead Castle, Bucks., and was buried in Hayles Abbey, Gloucs.
    Issue of marriage:

(i)
Richard
He was born in July, 1246, at Wallingford Castle, Berkshire; he died there on 15 August, 1246, and was buried at Grove Mile.
(ii)
Edmund
He was born on 26 December, 1249, or 5 December, 1250 at Berkhamstead Castle, Bucks., and was invested as Earl of Cornwall on 13 October, 1272. He died on 24/25 September, or 1 October, 1300, at Ashridge Abbey, Herts., and was buried in Hayles Abbey, Gloucs.
Edmund married, on 6 October, 1272, at Ruislip Chapel, Middlesex:
Margaret
She was the daughter of Richard de Clare, Earl of Gloucester and Hertford, by Matilda, daughter of John de Lacy, Earl of Lincoln; her father was the son of Richard of Cornwall’s first wife, Isabella Marshal. Margaret was born around 1249/50. She was either divorced or legally separated from her husband in February, 1293. She died in February, 1313 (or perhaps before 16 September, 1312), and was buried in Chertsey Abbey, Surrey. There was no issue of her marriage to Edmund.
(iii)
Richard (?)
He may have been born in c .1252, although he has perhapsbeen confused with Richard de Cornwall, Earl Richard’s illegitimate son. He was killed in 1296, at the siege of Berwick, by iron shot in his head.
    Richard married thirdly, on 16 June, 1269, at the Stiftkirche, Kaiserslauten, Germany:
    Beatrice
    She was the daughter of Dirk II, Count of Falkenburg, by Joan van Loon. (Her parentage is sometimes erroneously given as either (i) Walram de Fauquemont, Lord of Mountjoye, by Jutta, daughter of Otto, Count of Ravensburg, Westphalia, or (ii) Lothaire, Count of Hostade and Dalem, or (iii) Philip von Falkenstein, Arch-Chamberlain of the Empire. She was no connection of any of these.) Beatrice was born in c. 1253, probably at Falkenburg Castle, Germany. She died on 17 October, 1277, and was buried in the Church of the Franciscan Friars Minor, Oxford.
    3   Joan (under Alexander II, King of Scotland , see here ).
    4   Isabella
    She was born in 1214. She married Frederick II, King of Sicily, and Emperor of Germany ( d. 1250), on 20 July, 1235, at Worms Cathedral, Germany, and had issue:
    1  Jordan (?) ( b. & d .1236).
    2  Agnes ( b. & d .1237).
    3  Henry, King of Jerusalem (1238–1253).
    4  Margaret (1241–1270); she married Albert I, Margrave of Meissen and Landgrave of Thuringia and Misnes (1240–1315), and had issue.
    Isabella was crowned Empress of Germany on 20 July, 1235, at Worms Cathedral. She died on 1 or c. 6 December, 1241, at Foggia, near Naples, Italy, in childbirth, and was buried