| Name | Relationship with John FitzAlan | Civil | Canon |
|---|
| 3rd cousin 17 times removed | XXV | 21 |
| 3rd cousin 18 times removed | XXVI | 22 |
| 4th cousin 16 times removed | XXVI | 21 |
| Half 4th cousin 17 times removed | XXVII | 22 |
| 4th cousin 17 times removed | XXVII | 22 |
| 4th cousin 18 times removed | XXVIII | 23 |
| Half 4th cousin 18 times removed | XXVIII | 23 |
| Firth, Henry Heberton | 16th great-grandnephew | XX | 19 |
| 1st cousin 18 times removed | XXII | 20 |
| Half 2nd cousin 19 times removed | XXV | 22 |
| 3rd cousin 18 times removed | XXVI | 22 |
| 3rd cousin 19 times removed | XXVII | 23 |
| 4th cousin 17 times removed | XXVII | 22 |
| Half 4th cousin 18 times removed | XXVIII | 23 |
| 4th cousin 18 times removed | XXVIII | 23 |
| 4th cousin 19 times removed | XXIX | 24 |
| Half 4th cousin 19 times removed | XXIX | 24 |
| Firth, John | 13th great-grandnephew | XVII | 16 |
| 1st cousin 15 times removed | XIX | 17 |
| Half 2nd cousin 16 times removed | XXII | 19 |
| 3rd cousin 15 times removed | XXIII | 19 |
| 3rd cousin 16 times removed | XXIV | 20 |
| 4th cousin 14 times removed | XXIV | 19 |
| Half 4th cousin 15 times removed | XXV | 20 |
| 4th cousin 15 times removed | XXV | 20 |
| 4th cousin 16 times removed | XXVI | 21 |
| Half 4th cousin 16 times removed | XXVI | 21 |
| Firth, John | 14th great-grandnephew | XVIII | 17 |
| 1st cousin 16 times removed | XX | 18 |
| Half 2nd cousin 17 times removed | XXIII | 20 |
| 3rd cousin 16 times removed | XXIV | 20 |
| 3rd cousin 17 times removed | XXV | 21 |
| 4th cousin 15 times removed | XXV | 20 |
| Half 4th cousin 16 times removed | XXVI | 21 |
| 4th cousin 16 times removed | XXVI | 21 |
| 4th cousin 17 times removed | XXVII | 22 |
| Half 4th cousin 17 times removed | XXVII | 22 |
| Firth, Lucas Smith | 14th great-grandnephew | XVIII | 17 |
| 1st cousin 16 times removed | XX | 18 |
| Half 2nd cousin 17 times removed | XXIII | 20 |
| 3rd cousin 16 times removed | XXIV | 20 |
| 3rd cousin 17 times removed | XXV | 21 |
| 4th cousin 15 times removed | XXV | 20 |
| Half 4th cousin 16 times removed | XXVI | 21 |
| 4th cousin 16 times removed | XXVI | 21 |
| 4th cousin 17 times removed | XXVII | 22 |
| Half 4th cousin 17 times removed | XXVII | 22 |
| Firth, Maria Carpenter | 14th great-grandniece | XVIII | 17 |
| 1st cousin 16 times removed | XX | 18 |
| Half 2nd cousin 17 times removed | XXIII | 20 |
