John was 24 y.o. when his father died in May 1440, according to the Inquisition held then.
After the accession of Henry VII to the throne in 1485, he restored to John Fauntleroy, the Haudois estate in the Isle of Jersey, as being the next of kin to Geoffry le Walleys, who was killed at the battle of Barnet 1471 fighting on the Lancaster side.
1471 fighting on the Lancaster side against Edward IV and his lands attained. The family of le Walleys or Welsh was a prominent family bearing arms.