Agatha de Massey was born circa 1168 in England to Hamon III de Massey (c1129-c1216) and Agatha de Theray (c1140-aft1190) . She married Joscelyn de Hellesby (c1165-) .
Children
| Name | Birth | Death | Joined with |
| Adam de Hellesby | |||
| Joscelyn de Hellesby | |||
| Hamon de Hellesby | |||
| John de Hellesby (c1190-) | 1190 | Leuca Unknown | |
| Roger de Hellesby | |||
Siblings
| Name | Birth | Death | Joined with |
| Isabel de Massey (c1155-c1214) | 1155 England | 1214 England | Hugh de Dutton (c1152-1230) |
| Cicely de Massey (-1186) | 1156 England | 1186 England | Richard de Fitton (-1210) |
| Hamon IV de Massey (c1160-aft1250) | 1160 England, United Kingdom | 1250 England, United Kingdom | |
| Agatha de Massey (c1168-) | 1168 England | Joscelyn de Hellesby (c1165-) | |
| Hugh de Massey (c1170-) | |||