of the queen were forfeited (Acta Parl. Scot. iii. 45-8). With his brother, Lord John, he was concerned in the plot by which the regent Moray was assassinated (January 1570), and James Hamilton of Bothwellhaugh [q. v.], the murderer, subsequently applied to him by letter for assistance (Cal. State Papers, For. Ser. 1572-4, entry 4). On the forfeiture of Hamilton the abbey and lands of Paisley had been bestowed on Lord Semple, who placed a strong garrison in the castle. During a truce in 1571 Claud Hamilton surprised it and left a dependent, John Hamilton, with several men-at-arms, to hold it ; but the new regent, Lennox, by cutting off their water supply compelled them to surrender (Herries, Memoirs, p. 131). On 19 April of this year he was received by the queen's party into the castle of Edinburgh (Bannatyne Memorials, p. 111). He was one of the leaders of the daring attempt to capture the regent Lennox and the principal lords of the king's party at Stirling on 5 Sept. ; and the trooper Calder, who shot the regent, confessed that he did so by Hamilton's special instructions (confession in Cal. State Papers, For. Ser. 1569-71, entry 2023). It was also asserted that he had given directions that all the noblemen taken prisoners should be slain as soon as they were brought outside the port of the town (Calderwood, i. 139). On 3 July 1572 he and other Hamiltons were specially denounced as traitors (Reg. P. C. Scotl. ii. 155) ; but on the 10th of the same month he surprised Lord Semple while collecting rents from his tenants, killing forty-two of his men and taking sixteen prisoners (Hist. James the Sext, p. 113). By the 'pacification of Perth,' 23 Feb. 1572-3 (printed in Reg. P. C. Scotl. ii. 193-200), Hamilton was replaced in possession of his estates. Lord Semple refused to deliver up the house of Paisley, but Hamilton, on 10 June 1573, obtained a levy of forces to aid him in recovering it (ib. p. 241). In August 1574 Hamilton married Margaret, only daughter of George, sixth lord Seton, and took up his permanent residence at Paisley.
During Morton's regency (1573-8) Hamilton seems to have taken part in no schemes in behalf of Mary, although he was privy to the plot which led to Morton's fall in 1578. He and his brother John were still under sentences for their connection with the murders of the two regents, the question having been evaded in the pacification of Perth (ib. p. 198). The regent, however, agreed to refrain from action, and to be guided in the future by the advice of the queen of England. Her decision was that its consideration might be left over till King James came of age. They would probably have been unmolested, but when the king nominally assumed the government the old agreement no longer held, and Morton seems to have deemed it advisable, even for his own safety, no longer to spare them. On 30 April 1579 the council therefore suddenly issued an order for the revival of the old acts against them for the commission of the crimes, instruction being given for their immediate apprehension, and for the surrender of their houses and lands (ib. iii. 146-7). Both the Hamiltons, though taken completely by surprise, succeeded in effecting their escape. To conceal this they made ostentatious preparations for the defence of their principal strongholds. They entertained no hope of making any effectual resistance, but the bold attitude of their dependents in defending the castles led the government completely astray. When the castle of Paisley surrendered, it was found that 'Lord Claud was not in his strength, but had conveyed himself quietly to sic pairt as no man knows' (Moysie, Memoirs, p. 21). After remaining for some time in hiding in Scotland he made his way to the borders, where he was received by Sir John Forster. Elizabeth was naturally displeased at proceedings taken without her advice, and she was disposed to screen the Hamiltons on account of their near heirship to the Scottish crown. On 13 Sept. she sent a letter to King James excusing the conduct of Sir John Forster in harbouring Hamilton (Cal. State Papers, Scott. Ser. i. 399), and on the 16th sent Nicholas Arrington to Scotland to mediate on his behalf (ib.) Her mediation was unheeded, and at the parliament held in November doom of forfeiture was passed against the two Hamiltons and their principal associates. De Castelnau, the French ambassador, wrote to his master that Claud professed entire devotion to the French cause, but that it was expedient that the Hamiltons should owe their restoration rather to the mediation of France than to Elizabeth. Claud also himself wrote to Queen Mary, making an offer of his services (ib. ii. 929), and it was clear that he was devoted to her interests, although wholly dependent on Elizabeth for protection. For a time, however, he was compelled to act in direct opposition to the policy of Mary's representatives. The chief agents in expelling Morton from power Esme Stuart, duke of Lennox, and Captain James Stuart, recognised by the king as earl of Arran had been made to share the spoils of the Hamiltons [see under Hamilton, John (1532-1604)]. The French king, notwithstanding the remonstrances of De Castelnau, had declined to interfere on behalf of the Hamiltons, and as Claud had to depend for redress wholly on Elizabeth