Mohun was still a child when a long-running dispute about the family estates began in 1613 between his father Sir Reginald and his older half-brother John. One of the principal bones of contention was the future provision for Sir Reginald’s younger children; a number of fraudulent deeds benefiting Mohun seem to have been drawn up around this time, but they were subsequently destroyed. A bill presented to the Commons in 1621 by Sir Reginald was largely designed to ensure that, should John die without a male heir, his property would pass to Mohun or his younger brothers, but this measure failed at the committee stage.
The chronology of Mohun’s education allows him to be distinguished from his cousin and namesake, a mariner who was summoned before the Privy Council in 1622, and who captained several ships in the mid-1620s.
