990 - 1040 (50 years)
| Geoffrey DE PORHOET, Viscount of Porhoet in Brittany Bef 1105-1141 |
| Geoffrey DE PORHOET, Viscount of Porhoet in Brittany | |
| B: | Bef 1105 |
| D: | 1141 |
| Odo I DE PORHOET, Viscount of Britanny 1049-1092 |
| Odo I DE PORHOET, Viscount of Britanny | |
| B: | 1049 |
| D: | 1092 |
 | Ann DE LEON 1065-Yes, date unknown |
| Ann DE LEON | |
| B: | 1065 |
| D: | Yes, date unknown |
| Josselin DE PORHOET 1025-1074 |
| Josselin DE PORHOET | |
| B: | 1025 |
| D: | 1074 |
|
| Guithenoc DE PORHOET, Viscount 990-1040 |
| Guithenoc DE PORHOET, Viscount | |
| B: | 990 |
| Guillers, Brittany, (now France) | |
| D: | 1040 |
| Alluram 994-Yes, date unknown |
| Alluram | |
| B: | 994 |
| D: | Yes, date unknown |
