Isabel De Vere
- Yes, date unknown(
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- 1 Isabel De Vere [1] d. Yes, date unknown
- John (Lord Okehampton) De Courtenay d. 3 May 1274
- 2 Hugh (Sir) (of Okehampton) De Courtenay [1.1] d. 28 Feb 1290-1291
- Eleanor Le Despenser d. Aft Mar 1315
- 3 Eleanor De Courtenay [1.1.1] d. Yes, date unknown
- Henry (1st Lord Grey of Condor) De Grey d. 1308
- 4 Richard (2nd Lord Grey of Condor) De Grey [1.1.1.1] d. 1335
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- 4 Richard (2nd Lord Grey of Condor) De Grey [1.1.1.1]
- 3 Hugh (Earl of Devon) De Courtenay [1.1.2] b. 1274 d. 23 Dec 1340
- Agnes De St John d. 11 Jun 1345
- 4 Hugh (2nd\10Th Earl of Devon) Courtenay [1.1.2.1] b. 12 Jul 1303 d. 2 May 1377
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- 4 Hugh (2nd\10Th Earl of Devon) Courtenay [1.1.2.1]
- 3 Margaret De Courtenay [1.1.3] d. Yes, date unknown
- + Nicholas (2nd Lord Moels) De Moels d. Bef 29 Jan 1315
- + Nicholas (2nd Lord Moels) De Moels d. Bef 29 Jan 1315
- 3 Isabel (of Okehampton) Courtenay [1.1.4] d. Yes, date unknown
- John (of Basing 1st Lord) De St John b. Abt 1273 d. Bef 4 Apr 1329
- 4 Margaret (of Basing) St John [1.1.4.1] b. Abt 1308 d. 19 Nov 1361
[ =>]
- 4 Isabel St John [1.1.4.2] b. 29 Jun 1333 d. 16 Oct 1393
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- 4 Margaret (of Basing) St John [1.1.4.1]
- 3 Eleanor De Courtenay [1.1.1]
- 2 Hugh (Sir) (of Okehampton) De Courtenay [1.1]