| Name | Frederik Andries David GRUL |
| Birth | 11 Mar 1938, Warnsveld, Gelderland, Nederland |
| Occupation | Instrument-maker |
| Father | Andries David GRUL (1898-1964) |
| Mother | Frederika MEIJERINK (1899-1989) |
| 1 | Yke de JONG |
| Birth | 10 Jul 1941, Oudehaske, Friesland, Nederland |
| Occupation | Hoofd-keuken |
| Father | Klaas Egbert de JONG (1909-1997) |
| Mother | Anna BRANDSMA (1920-) |
| Marriage | 10 Dec 1965, Langweer, Doniawerstal, Friesland, Nederland |
| Children | Andries David (1967-) |
| Anny Clara (1970-) |