On 26 October 1605 the Catholic nobleman William Parker, 5th Lord Monteagle, received an anonymous letter urging him to absent himself from the forthcoming session of Parliament, due to open on 5th November. This missive, the first significant hint of the Gunpowder Plot, warned mysteriously that those attending ‘shall receive a terrible blow … and yet they shall not see who hurts them’. Monteagle took the letter to Court, where he showed it to the secretary of state, Robert Cecil, 1st earl of Salisbury. The earl was initially sceptical of the letter, in part because he thought it ‘very improbable that only one nobleman should be warned and no more’ (Winwood’s Memorials ed. E. Sawyer, ii. 171). At this date there were perhaps as many as 17 Catholic members of the House of Lords and, unlike the Commons, there was nothing to prevent them from taking their seats. Consequently, it was likely that had the conspirators succeeded, they would have blown up several of their most powerful coreligionists, at the very moment when they needed the support of the Catholic peerage for their intended new regime.
Unsurprisingly, the subsequent investigation into the plot revealed that preventing Catholic peers from attending Parliament on 5 November had been a lively issue of debate among the conspirators. Some of them, notably Robert Catesby and Thomas Winter, feared that warnings would compromise the security of the plot. Catesby said he would rather the Catholic nobility were blown up than that the plot should fail. Moreover he contemptuously dismissed these peers as ‘atheists, fools and cowards’, thereby expressing tensions within the Catholic community over the widespread tendency of its most prominent lay members to seek accommodation with the Protestant authorities rather than suffer for their beliefs. Nevertheless, he found it necessary to assure his colleagues that ‘tricks’ would be used to keep the Catholic peers safe – and such undertakings reinforced the authorities’ assumption that Monteagle was not the only lord who had been warned to stay away (D. Jardine, A Narrative of the Gunpowder Plot, 73-8).
Following the arrest of Guy Fawkes and the exposure of the plot, certain peers came under immediate scrutiny. Foremost among them was Anthony Maria Browne, 2nd Viscount Montagu, whom Catesby had definitely approached. During the previous session, on 25 June 1604, Montagu had made an outspoken defence of the Catholics in the upper House, for which he was briefly imprisoned. His reputation as a champion of his faith, together with the fact that he had been absent from Westminster on 5 November, quickly aroused the government’s suspicions, and he was taken into custody on the 7th. In addition the presence of Robert Keyes among the plotters undoubtedly brought Keyes’ employer, Henry, 4th Lord Mordaunt, to the attention of the authorities. Mordaunt had also been absent on 5 November and ten days later both he and Viscount Montagu were sent to the Tower. The following day Guy Fawkes revealed that Francis Tresham had been ‘exceeding earnest’ with Catesby and Winter to ensure that his brother-in-law, Monteagle, was forewarned. Ever since then, it has been generally assumed that it was Tresham who wrote the anonymous letter. According to Fawkes, the conspirators were also informed that Edward, 10th Lord Stourton, another of Tresham’s brothers-in-law, ‘by accident’ would not be attending the start of the session (TNA, SP 14/216/1, f. 150). This revelation brought Stourton to the attention of the authorities; he had indeed been absent on the 5th, and he was promptly dispatched to the Tower. However, such absences alone were apparently not enough to render a Catholic lord suspect. No action was taken against John, 1st Lord Petre, Thomas, 3rd Lord Darcy of Chiche, or several other Catholic peers, even though they were also missing from the Lords that day.
Mere knowledge of treason, without informing the authorities, is in itself a serious felony, termed misprision of treason. By late February 1606 the government had decided not to arraign Montagu, Mordaunt and Stourton for that offence, the king having concluded that they stayed away on 5 November because of ‘some general advises in respect of uncertain troubles’, rather than specific warnings (J. Hunter, Hallamshire ed. A. Gatty, 122; J. Hawarde, Les Reportes del Cases in Camera Stellata, 438). Nevertheless, the suspicions about their conduct lingered, and it was felt necessary to take some exemplary action against them. At the very least, all three were guilty of absenting themselves from Parliament without having first secured the king’s permission. Mordaunt and Stourton were duly put on trial in Star Chamber the following June, though Montagu was spared through the influence of the lord treasurer, his father-in-law Thomas Sackville, 1st earl of Dorset. Mordaunt and Stourton were heavily fined and sentenced to remain imprisoned during the king’s pleasure. In the event Mordaunt’s fine was never collected, while Stourton only paid a quarter of his. Even so, the former was probably still under some form of restraint when he died in 1609, and the latter did not fully regain his liberty until ten years later.
Biographies of all the peers mentioned will appear in the History of Parliament’s forthcoming volumes on the House of Lords 1604-1629.