Family: Sir William 1st Lord DE ATON / Isabel DE PERCY (F1099)
m. 1340 | Sir Henry IV 2nd Baron Percy of Alnwick DE PERCY (1301-1352) 
|
 | Idonea Baroness Percy DE CLIFFORD (1303-1365) |
| Maud Baroness Neville DE PERCY (1335-1377) |
| Eleanor DE PERCY (1326-1368) |
| Sir Henry V 3rd Baron Percy of Alnwick DE PERCY (1322-1368) |
| Sir William 1st Lord DE ATON (1318-1388) |
| Isabel DE PERCY (1326-1368)
|
| Anastasia DE ATON (1353- )  |
| Catherine DE ATON (1367-1422) |