accession, Northumberland welcomed the new monarch with apparent enthusiasm. He was at once made a privy councillor and captain of the band of gentleman pensioners, and next year (1604) was nominated joint lord lieutenant for Sussex and, with some inconsistency, a commissioner to expel Jesuits and seminary priests. On 30 Aug. 1605 he was created M.A. at Oxford. But the king's methods of government did not satisfy him. He and his wife had vigorously protested against the punishment of their friend Sir Walter Raleigh, and the persecution of the catholics had not been relaxed. The court was overrun by Scotsmen, for whom Northumberland acquired an antipathy. He is said, moreover, to have perceived that Prince Henry was likely to prove a more sagacious ruler than his father, and courted the prince's society more than James approved. In the autumn of 1605 he retired from court to Syon House, with the apparent intention of forsaking politics for the more congenial study of science and literature.
On the discovery of the 'gunpowder plot' of 5 Nov. 1605 some suspicion of complicity fell upon Northumberland. His kinsman Thomas Percy, one of the chief conspirators, had dined on 4 Nov. with Northumberland at Syon House. Lord Salisbury, whose relations with Northumberland were never cordial, deemed it prudent to commit the earl to the care of the archbishop of Canterbury at Croydon, 'there to be honourably used until things be more quiet.' Lord Salisbury informed a correspondent, Sir Charles Cornwallis, that no thought was harboured in the council that the earl was responsible for the plot. His arrest was only 'to satisfy the world that nothing be undone which belongs to policy of state when the whole monarchy was proscribed to dissolution' (Winwood, Memorials, ii. 172). On the 11th, in a letter to the council, Northumberland appealed to his habits of life as proof that his interests lay elsewhere than in political conspiracy. 'Examine,' he said, 'but my humours in buildings, gardenings, and private expenses these two years past.' He had few arms, horses, or followers at Syon, and had known none of the conspirators excepting Percy. On 27 Nov., however, he was sent to the Tower.
On 27 June 1606 he was tried in the court of Star-chamber for contempt and misprision of treason. It was stated that he had sought to become chief of the papists in England; that knowing Thomas Percy to be a recusant he had admitted him to be a gentleman pensioner without administering to him the oath of supremacy; that after the discovery of the plot he had written to friends in the north about securing his own moneys, but gave no orders for Percy's apprehension. He pleaded guilty to some of the facts set forth in the indictment, but indignantly repudiated the inferences placed upon them by his prosecutors. He was sentenced to pay a fine of 30,000l, to be removed from all offices and places, to be rendered incapable of holding any of them hereafter, and to be kept a prisoner in the Tower for life.
Northumberland emphatically protested to the king against the severity of this sentence, and his wife appealed to the queen, who had shown much kindly interest in him. But the authorities were obdurate. The king insisted that 11,000l. of the fine should be paid at once, and, when the earl declared himself unable to find the money, his estates were seized, and funds were raised by granting leases on them. The leases were ultimately recalled, and the earl managed to pay 11,000l on 13 Nov. 1613; but more than seven years of imprisonment still awaited him.
Northumberland gathered about him in the Tower men of learning, to whom he paid salaries for assisting him in his studies. Thomas Harriot, Walter Warner, and Thomas Hughes, the mathematicians, were regular attendants and pensioners, and were known as the earl's 'three magi.' Nicholas Hill aided him in experiments in astrology and alchemy. He also saw something of his fellow-prisoner, Sir Walter Raleigh. A large library was placed in his cell, consisting mainly of Italian books on fortification, astrology, and medicine. But Tasso and Machiavelli were among them. His only English works were Chapman's Homer, 'The Gardener's Labyrinth,' Daniel's 'History of England,' and Florio's 'Dictionary' (Fonbanque, ii. 626 sq.) A part of his time was occupied in writing his 'Advice to his Son (Algernon) on his Travels,' which was printed from the manuscript at Alnwick in the 'Antiquarian Repertory,' iv. 374. For some years his second daughter, Lucy, was his companion in the Tower. She formed a strong affection for James Hay, afterwards Earl of Carlisle, and resolved to marry him. Northumberland disliked Hay as a Scotsman and a favourite of the king, and declined to sanction the union. The marriage, however, took place in 1617. Thereupon Hay, in order, apparently, to overcome Northumberland's prejudice against him, made every effort to obtain his release. In this he at length proved successful. In 1621 James was induced to celebrate his birthday by setting Northumberland and other political prisoners at liberty. The earl showed
