He was also a double agent working for Sir Francis Walsingham.
In 1586, Mary, Queen of Scots was accused by the British Government of having received and written letters about a plot to assassinate Queen Elizabeth. Paget, alongside with Thomas Morgan, was named in Mary's trial as one of the correspondents, and a letter to him dated 17 July 1586 formed part of the evidence at her trial. Queen Elizabeth demanded Paget's extradition from France, and threatened to have him assassinated if he remained.
Early in 1588, Paget moved to Brussels, where he remained for the next eleven years, until 13 July 1603, when he returned to Paris after the death of Queen Elizabeth when it was safe for him to do so. He was able to recover both his manor at Weston-on-Trent and a pension from King James. He died at the beginning of February 1612, leaving his lands to the sons of one of his sisters, the Roper family. It was Anthony Roper who built the hall at Weston.
Under his father's will he became entitled to the manor of Weston-Aston and other lands in Derbyshire. He was a zealous Roman Catholic, and left England, in discontent with its ecclesiastical constitution, around 1572, and fixed his residence in Paris. There he became secretary to James Beaton, archbishop of Glasgow, who was Queen Mary Stuart's ambassador at the French court, and he was soon joined in the office with Thomas Morgan (1543-1606 ?) Morgan and Paget were in constant correspondence with Claude de la Boisseliere Nau and Gilbert Curie, the two secretaries who lived with the queen in England, and they four governed from thenceforth all the queen's affairs at their pleasure. Paget and Morgan secretly opposed Archbishop Beaton, Mary's ambassador, and wrung from him the administration of the queen's dowry in France, which was about thirty million crowns a year. Joining themselves afterwards with Dr. Owen Lewis in Rome, and falling out with Dr. Allen and Father Parsons, they were the cause of much division among the catholics Parsons states that the original cause of Paget and Morgan's division from Dr. Allen and himself was their exclusion, by desire of Henry I, Duke of Guise and the Archbishop of Glasgow, from the consultation held at Paris in 1582 relative to the deliverance of the Queen of Scots, and the restoration of England to catholic unity by means of a foreign invasion (ib. ii. 392). Thenceforward Paget and Morgan inspired Mary with distrust of Spain and the Jesuits.
During all this time, while apparently plotting against Queen Elizabeth, Paget was acting the part of a spy, and giving political information to her ministers. In 8 January 1581-1582 he wrote from Paris to Secretary of State, Frances Walsingham in these terms :
God made me known to you in this town, and led me to offer you affection ; nothing can so comfort me as her Majesty's and your favour.Again he wrote, on 28 September 1582 :
In my answer to her Majesty's command for my return to England, assist me that she may yield me her favour and liberty of conscience in religion. . . . If this cannot be done, then solicit her for my enjoying my small living on this side the sea, whereby I may be kept from necessity, which otherwise will force me to seek relief of some foreign prince.
On 23 October 1582 he informed Walsingham of his intention to go to Rouen for his health, and to drink English beer. He professed dutiful allegiance to Elizabeth, and his readiness to be employed in any service, matter of conscience in religion only excepted.
Lord Paget, writing to his brother on 25 October in the same year, said his stay in Rouen was more misliked than his abiding in Paris, considering that he consorted with men like the Bishop of Ross. He added that
he was sorry to hear by some good friends that he carried himself not so dutifully as he ought to do, and that he would disown him as a brother if he forgot the duty he owed to England.From this letter it would seem that Lord Paget's interview with his brother at Petworth must have been of a more innocent character than has been generally supposed. However, about the end of November Lord Paget fled to Paris, and thenceforward became suspected of complicity in all his brother's treasons. On 2 December 1583, Sir Edward Stafford, the English ambassador to France, wrote from Paris to Sir Fances Walsingham :
Lord Paget, with Charles Paget and Charles Arundel, suddenly entered my dining chamber before any one was aware of it, and Lord Paget says they came away for their consciences, and for fear, having enemies. They also told him that for all things but their consciences they would live as dutifully as any in the world.
From this period Charles Paget, in conjunction with Morgan and other malcontents at home and abroad, continued their machinations, which were, of course, well known to the English government; and in June 1584 Stafford, the English ambassador, made a formal demand, in the name of Queen Elizabeth, for the surrender of Lord Paget, Charles Paget, Charles Arundel, Thomas Throckmorton, and Thomas Morgan, they having conspired against the life of the English queen. The king of France, however, refused to deliver them up, although he soon afterwards imprisoned Morgan, and forwarded his papers to Queen Elizabeth.
It is clear that Paget was regarded with the utmost distrust and suspicion by Walsingham, who, in a despatch sent to Stafford on 16 December 1584, says : Charles Paget is a most dangerous instrument, and I wish, for Northumberland's sake, he had never been born. In May 1586 Paget, on account of illness, went to the baths of Spain. He was attainted of treason by act of parliament in 1587.
Although all his plots had signally failed, he appears still to have clung to the idea that the Protestant religion in England could be subverted by a foreign force. Writing under the signature of 'Nauris,' from Paris, to one Nicholas Berden alias Thomas Rogers, 31 January 1587-1588, he observed, in reference to the anticipated triumph of the Spanish Armada :
When the day of invasion happens, the proudest Councillor or Minister in England will be glad of the favour of a Catholic gentleman.In the same letter he stated that all Walsingham's alphabets or ciphers had been interpreted by him.
He continued his correspondence:
I am incited to boldness with you by your favour to my nephew Paget, and the good report I hear of your sweet nature, modesty, and wisdom. I desire ardently to do a service agreeable both to the queen and the king of Spain. I am under obligation to the one as an English subject, and to the other as a catholic prince who has relieved me in my banishment.He added that
His Highness ' was willing to treat with allies, and particularly with the queen, that the crowns of England and Spain might return to their old amityOn 27 April 1598 he wrote from Liege to Thomas Barnes in London: I am unspeakably comforted that the queen inclines to listen to my humble suit. The profits of my land are worth £200 a year to myself; it is a lordship called Weston-upon-Trent. ... I cannot capitulate with the Queen; but the greater my offence has been, the greater is her mercy in pardoning and restoring me to my blood and living, showing the liberality which makes her famous, and obliging me to spend my life at her feet.
Animated by intense hatred of the Spanish faction, Paget lost no time after his arrival at Paris in putting himself in communication with Sir Henry Neville [q. v.], the English ambassador, who forwarded a detailed account of the circumstances to Sir Robert Cecil in a despatch dated 27 June (O.S.) 1599. Cecil seems to have been by no means anxious to encourage Paget, but Neville was more favorable to him. Paget said he felt himself slighted by the English government, but he nevertheless seems to have given from time to time important intelligence to Neville and to Ralph Winwood the succeeding ambassador at the French court. His attainder appears to have been reversed in the first parliament of James I, probably by the act restoring in blood his nephew William, Lord Paget, and it is presumed that he returned to England. His paternal estate, including the manor of Weston on Trent and other manors in Derbyshire, was restored to him on 13 July 1603; and on 18 August in the same year James I granted him £200 per annum, part of a fee-farm rent reserved by a patent of Queen Elizabeth, bestowing the lands of Lord Paget on William Paget and his heirs. He died, probably in England, about the beginning of February 1611-1612, leaving a good estate to the sons of one of his sisters.