| Father | Baron William De Montacute (Montague) (1275 - 1319) |
| Mother | Elizabeth De Montfort (1275 - 1345) |
| Sibling | Alice Montacute (1311 - 1345) |
| Sibling | Mary De Montagu (Montacu (1313 - 1359) |
| Sibling | Hawise De Montacute (1317 - 1361) |
| Sibling | Sir Edward De Montagu (1309 - 1342) |
| Sibling | Simon Montague (1303 - 1345) |
| Sibling | Isabel De Montacute (1315 - 1390) |
| Sibling | Matilda De Montagu Abbess of Barking (1319 - ) |
| Sibling | William De Montagu , 1st Earl of Salisbury, Lord of The Isle of Mann (1307 - 1344) |
| Sibling | Lady Katherine De Montague (1315 - 1343) |
| Sibling | Mary De Montague (1303 - ) |
| Sibling | Maud Montacute (1307 - ) |
| Sibling | John De Montacute (Montague) (1299 - ) |
| Sibling | Isabel Montacute Montague (1319 - ) |
| Sibling | Elizabeth De Montacute (1305 - 1359) |