The Mohun family traced their ancestry back to the Norman Conquest, via the medieval barons of Dunster, Somerset. Around the fourteenth century they settled in Cornwall, where they established a seat at Hall, overlooking Fowey harbour. By 1588 they had accumulated more than 20 manors in the county, particularly in the district between Fowey and Lostwithiel. In addition, Mohun’s grandfather was a joint heir to the former estates of the Courtenay earls of Devon, while his father Sir William, who purchased Boconnoc manor in 1579, acquired by marriage a share in the Horsey family’s Dorset lands.
Mohun first entered Parliament as a Fowey burgess during the 1580s, but competition from within the borough had largely eliminated his electoral influence there by 1604, when he seems to have used his standing at East Looe to present one of its places to his second cousin Sir Robert Phelips. At this juncture he may also have exercised some leverage at St. Mawes, for his half-brother William owned a manor nearby, and in 1602 Mohun himself had become a trustee to the major local landowner, Charles Trevanion*, who was then a minor. This combination of factors explains why one of the borough’s seats went to the Mohuns’ brother-in-law Sir John Specott.
Through his first marriage Mohun possessed a tenuous claim to kinship with lord treasurer Salisbury (Robert Cecil†), who may have pressured him into purchasing Cornwall’s first baronetcy in November 1611. Whatever the circumstances, his new title re-affirmed his social ambitions, though the requirement to pay £1,095 in connection with this honour may have contributed to his financial difficulties.
In the 1614 parliamentary elections, Mohun took one of the East Looe seats himself, and presented the other to his then wife’s brother George Chudleigh. His niece’s husband Sir Nicholas Smith found a place at St. Mawes.
During 1614 the wrangling between Mohun and his heir intensified, John alleging that further fraudulent deeds had been drawn up. An attempt at arbitration during Chancery proceedings in 1616 proved abortive, and by 1620 Mohun had resolved to seek a parliamentary solution.
During 1622 a batch of Mohun suits were heard in Chancery, and a deal was finally reached, though a revised parliamentary bill was thought necessary to confirm the agreement.
In 1625 Mohun and Sir George Chudleigh were returned for Lostwithiel, but so too were two other men, and it is uncertain whether the Commons ever resolved which of the four was entitled to sit. Mohun patronage may have helped (Sir) James Bagg II obtain his seat at East Looe but, despite Bagg’s subsequent close relationship with the family, hard evidence is lacking. In 1626 Bagg again secured a place at the same borough, while Mohun, who successfully nominated his younger son Reginald at Lostwithiel, deputed his patronage over the remaining East Looe seat to Sir George Chudleigh, who presented it to his own son John, after first offering it to (Sir) John Coke*.
From 1625, the large-scale billeting of soldiers in the districts of Cornwall closest to Plymouth kept Mohun at the forefront of local affairs. He was apparently one of the county’s more vigorous deputy lieutenants, and he displayed similar confidence as a commissioner for billeting, complaining to the Privy Council within weeks of his appointment about the soldiers’ level of allowance.
During the 1628 parliamentary elections Mohun’s patronage followed its customary pattern. His brother-in-law Sir John Chudleigh owed his place at Lostwithiel to him, and Paul Specott was again returned at East Looe. However, Mohun also played a central role in the scandal surrounding his son’s efforts to manage the Cornish shire election. On 8 Feb. Coryton chose a meeting with him, Grenville and Wrey to announce his intention to stand. Mohun’s signature featured prominently on the letters sent out during the next three weeks, which warned Coryton and Eliot to withdraw, and sought to rally support against them. He was apparently present at the gathering which nominated John Mohun and Sir Richard Edgcumbe* as alternative candidates for knights of the shire, though he thought better of attending the election itself, where Coryton and Eliot were overwhelmingly chosen.
By November 1629 the uneasy truce between Mohun and his heir over their estates had collapsed, and John sued his father for allegedly wasting the Boconnoc estates, in breach of the 1624 Act. Denying the charge, Mohun appealed to lord keeper (Sir Thomas) Coventry* against his son’s behaviour, but the outcome of these events is not known.
