According to a pedigree entered in the Heralds' Visitation of Devon in 1620, Thomas Mohun of Tavistock then living was son of Thomas, son of Thomas, serjeant-at-arms to Henry the Eighth, son of Thomas, son of Thomas, son of Lawrence one of the younger sons of Sir John Mohun of Dunster, who is otherwise known to have died in 1330. It is, however, very unlikely that six generations covered three centuries.
THOMAS MOHUN, the serjeant-at-arms, married Agnes daughter of William Amadas, who married secondly Thomas Stoford of Dolton, thirdly John Charles, and fourthly William Abbot of Hartland, who died in 1570.
THOMAS MOHUN, son of Thomas and Agnes, married Joan daughter of William Kedley (or Ridley) alias Pointer, and had issue:—
- Thomas, heir to his father.
- Charles, who died without issue.
- Eleanor, married firstly to Thomas Harris and secondly to William Grafton.
- Joan, married firstly to Richard Edgcumbe, secondly to Christopher Wolridge, thirdly to Erasmus Drewe, and fourthly to Alexander Maine.
- Denise, married firstly to Ralph Taylor and secondly to John Eliot.
- Dorothy, married to William Carden.
THOMAS MOHUN, son of Thomas and Joan, living in 1620, married firstly Grace, daughter of Richard Singleton of Truro, and by her had issue:—
- Thomas, born about 1600. He had a son Reynold, who was baptized in August 1628.
- William, born about 1607.
- Peter, of Cheriton Fitzpaine, born about 1609, and died in 1654, when his wife Joan was living.
- Frances, born about 1598, married in May 1616 to William Moore. She died in 1671.
- Denise, born about 1604.
He married secondly, in October 1614, Joan daughter of John Harris and had issue:—
- Ellis, baptized on the 6th of August 1615.
- Edward, born about 1617.
- John, baptized on the 26th of April 1621.
- Richard, baptized on the 30th of April 1628.
- Grace, baptized on the 28th of September 1616, buried in April following.
- Alice, baptized on the 19th of December 1618.
- Elizabeth, baptized on the 19th of March 1623.
This section is founded upon the pedigrees given in Vivian's Visitations of Devon (pp. 1, 12, 168, 321, 566, 574, 712), which furnish some particulars not to be found in the original MS.