Family: Sir William 1st Lord de Aton / Isabel de Percy (F1687)
m. 1340 | Sir Henry IV 2nd Baron Percy of Alnwick de Percy (1301-1352) 
|
 | Idonea Baroness Percy de Clifford (1303-1365) |
 | Sir Henry V 3rd Baron Percy of Alnwick de Percy (1322-1368) |
| Eleanor de Percy (1326-1368) |
| Maud Baroness Neville de Percy (1335-1377) |
 | Sir William 1st Lord de Aton (1318-1388) |
 | Isabel de Percy (1326-1368)
|
| Anastasia de Aton (1353- )  |
 | Catherine de Aton (1367-1422) |