Monson could trace his ancestors in Lincolnshire back to 1378, but the family was of little account before Tudor times, and the only previous Member of Parliament was his great-uncle Robert, a judge and zealous Protestant.
On the accession of James I, Monson attached himself to the Howards, especially the crypto-Catholic Henry Howard, earl of Northampton, and he was briefly in the running to become chancellor to the queen. Considered by Sir Anthony Weldon to be the best falconer in Europe, Monson stood high in the king’s favour, although a royal recommendation of his petition for a new office to survey the goods of felons and fugitives seems to have taken no effect.
In the second session, Monson was chosen as an arbitrator over a private bill concerning a Norfolk gentleman named John Holdich, who was in dispute with his tenants (23 May 1606); however, he failed to attend the meeting, at which only one committeeman was present, and the bill was subsequently allowed to sleep.
During the recess which followed the third session, Monson was granted the benefit of six recusancies.
At the 1614 general election Monson tried to re-establish his family’s political influence in Lincoln by putting up his brother, Sir Robert, but the antagonism roused by the recent Star Chamber case and the established interest of Sir Thomas Grantham* proved too strong and the attempt failed.
Monson’s political career was brought to an end by his alleged involvement in the murder of Sir Thomas Overbury. It was claimed that, to oblige the future countess of Somerset and the earl of Northampton, he had procured the appointment of Richard Weston, who administered the poison, as under-keeper at the Tower. Moreover, in his speech beneath the gallows, Sir Gervase Elwes, the lieutenant of the Tower, implicated Monson in the plot, and evidence from other sources indicated that some of the poisoned food had certainly passed through his house. He was arrested and arraigned at the Guildhall on 4 Dec. 1615, where Sir Edward Coke* accused him of atheism, and hinted at the existence of as yet unrevealed crimes and plots against the state. Monson pleaded for Suffolk, now lord treasurer, to be present at his trial to answer two questions, but Suffolk claimed he could neither help nor hinder the case. The trial was deferred, and Monson, protesting his innocence, was stripped of office and remanded to the Tower, where he remained for a year. Coke had agreed to the delay because he hoped to obtain evidence from Monson to prove that Overbury’s murder was an attempt to hide the existence of a pro-Spanish, pro-Catholic plot involving Somerset. The reported view of James that the evidence against Monson was weak, coupled with Coke’s fall from favour, eventually led to Monson’s release on bail and then to his pardon in January 1617.
Monson’s fortunes were now at a low ebb. His unsuccessful attempt in January 1618 to present his nephew, William Monson*, as a rival to Buckingham for the king’s affections, together with the fall of the Howards, prevented a speedy return to favour. He was not re-admitted to Court until July 1620, and was not restored as master falconer or to his other former offices. He also fell into difficulty as a result of standing surety for the defaulting ordnance official Sir Roger Dallison*.
