The scheme of a general rising was designed for the purpose of stifling the projected union; but the attempt having failed, the Jacobites were compelled to debate the treaty, clause by clause, in open parliament, where, notwithstanding every artifice for exciting public clamour, it was triumphantly carried. Lockhart, through the whole, was uniform in his opposition—adhered to every protest that was taken against it, and, in more than one instance, entered protests against it in his own name. He also, in conjunction with Cochrane of Kilmaronock, gave fifty guineas to Cunningham of Eckatt, for the purpose of forwarding a design of forcibly dispersing the parliament by an army of Cameronians, which he proposed to raise in the western shires, but which, as he alleged, he was prevented from doing by the intrigues of the duke of Hamilton.

The union having been ratified by the parliaments of both kingdoms, and peaceably carried into effect, the next hope of the Jacobites was the French invasion, which Hooke had negotiated with them during the preceding year, and to which they now looked forward with the most ardent expectation. Of all the partizans of James, perhaps none were more zealous, on this occasion, than the subject of this memoir; but, fortunately for himself, he followed in the train, and acted by the advice of the duke of Hamilton, who, being at the time at his seat in Lancaster, and taken there into custody by a king’s messenger, could not meet his Scottish friends at Dumfries, according to agreement, till the defeat of the French fleet rendered any further appearance at that time unnecessary, in consequence of which he himself, as well as his friends, escaped any thing like serious prosecution. Mr Lockhart also having the powerful influence of his uncle, lord Wharton, exerted in his favour, remained unmolested.

The next hope of the Jacobites was in the inclinations of the queen, which, with all her coldness, they naturally expected, and indeed had, if we may believe their own account, and lay much weight on a few occidental circumstances, a well-grounded hope, that they might be extended to her brother and his family; and that they might more effectually influence her counsels, it was resolved, that no influence or endeavour should be spared in procuring seats in parliament for the heads of the party. Mr Lockhart started for the county of Edinburgh, and had sufficient interest to secure his election, though he was obnoxious both to the court and the presbyterians, to whom he seems to have been always inimical. The first session of the first British parliament, did not afford much scope for that species of ingenuity for which Mr Lockhart has taken so much credit to himself; and by his efforts, joined to those of Mr Houston, younger of Houston, Lag, younger of Lag, Duff of Drummure, and Cochrane of Kilmaronock, all unwavering supporters of the same political creed, little or nothing was effected. The next session was almost wholly occupied with the affair of Sacheverel, in whose behalf the Jacobites were joined by those supporters of the house of Hanover, who either conceived, or for political purposes alleged, that the church was in danger, while the affairs of Scotland were neglected amidst more exciting discussions. A field was soon, however, to be opened, in which they doubted not shortly to reap a rich harvest.

At the period when a waiting woman in the queen’s bed-chamber was sapping the foundation of the Godolphin and Marlborough administration, that ministry requested leave to dismiss Mrs Masham, threatening her with an address from the two houses of parliament; to which was to be attached an invitation to Prince George, of Hanover. "As such treatment much chagrined the queen against her ministry," says Lockhart, "she was very desirous to secure herself against such attempts, and did avowedly solicite a great many members of both houses of parliament, that they would not consent to a motion to deprive her of the liberty allow’d to the meanest housekeeper in her dominions, viz., that of choosing her own domestic servants."—"And I accordingly," continues the narrator, in a very remarkable passage bearing on one of the most obscure points in British history, "procured an address, in a very high monarchical style, from the barons and freeholders in the county of Edinburgh; and having brought it up with me when I came to parliament, I was introduced by the duke of Hamilton to present the same; and having read it to her majesty, she seemed very well pleased, gave a gracious return to the address, and then told me, tho’ I had almost always opposed her measures, she did not doubt of my affection to her person, and hoped I would not concur in the design against Mrs Masham, or for bringing over the prince of Hanover. At first I was somewhat surprised, but recovering myself, I assured her I should never be accessary to imposing any hardship or affront upon her; and as for the prince of Hanover, her majesty might judge, from the address I had read, that I should not be acceptable to my constituents, if I gave my consent for bringing over any of that family, either now or any time hereafter. At this she smiled, and I withdrew; and then she said to the duke, she believed I was an honest man; and the duke replied, he could assure her I liked her majesty and all her father’s bairns." [Lockhart Papers, i. 307.]The gradual steps towards a delicate and dangerous subject, so naturally laid down in this valuable passage--the hope expressed by the queen that the Jacobite partisan was averse to the removal of the favourite, and the introduction of the prince—the surprise of the Jacobite, and his ingenious extension of the request--the queen’s smile and remark on his honesty—and, finally, the cautious but bold extension of the insinuations in the kindly rejoinder of the duke, all speak to the authenticity of the scene, and the accurate observation of the narrator. That he may be depended on, there is little doubt. The cautious Hallam considers that the Lockhart Papers sufficiently prove that the author "and his friends were confident of the queen’s inclinations in the last years of her life, though not of her resolution." Nor can a vanity to be esteemed the depository of the secrets of princes, be likely to operate on a man whose works are not to be witnessed by his own age. On the whole, the passage may be said almost to prove that the queen’s "inclinations" were with her brother; but a "resolution" on either side, she appears to have never attained.

The circumstance last mentioned was soon followed by the renowned downfall of Anne’s whig ministry. Strong but ineffectual attempts were made by the whigs at the elections. Lockhart was violently opposed in Edinburghshire, but carried his election by a great majority, as did Sir Hugh Paterson of Bannockburn for the shire of Stirling, and Sir Alexander Areskine, lord lyon king at arms, for the shire of Fife, both thorough paced Jacobites and violent episcopalians. The last of these gentlemen, along with Mr Carnegie of Boysack, Mr James Murray, second son to the viscount Stormont, afterwards created by the Pretender lord Dunbar, and Sir Alexander Cuming of Cantar, joined Mr Lockhart in a close confederacy, agreeing to mutual support, in cordially prosecuting the great objects for which they had come into parliament, viz., the dissolving of the treaty of union, and the breaking up of the protestant succession. Keeping their agreement as secret as was compatible with its efficacy, and prudently cultivating the friendship of the English tories, they soon became conspicuous, and were regarded by both sides of the house as men of superior consequence, whose feelings and views it was necessary to consult in all measures regarding Scotland. The first fruit of this confederacy was a broach of the union, committed by the house of lords, in reversing a sentence of the magistrates of Edinburgh which shut up the meeting-house of a Mr Greenshields, the first clergyman who introduced the English liturgy into the service of the Scots Episcopal church. The full harvest was the act of toleration, with the oath of abjuration annexed, to be imposed upon all the ministers of the Scottish church; the act restoring lay patronage; and the act for the observing certain holidays, all of which were prepared by Mr Lockhart, and by him and his friends forced upon the ministry, contrary to the expressed opinion of the people, and with the avowed purpose of undermining the presbyterian interest.

At the same time that he was so deeply engaged in forwarding the particular views of himself and his friends, in regard to affairs purely Scottish, Mr Lockhart was also employed upon the more general business, or what may be called the drudgery of the house. He was one, and the only Scotsman, who was upon the commission of the house for examining the national accounts, with the view of criminating the ex-whig ministers; and, as chairman of that commission, gave in a long report, intended to implicate the duke of Marlborough, a person whose conduct was certainly not pure, while it still affords a pleasing contrast to that of his accusers. The report, however, when it came to be examined, discovered only the headstrong party spirit of its authors, and not much against the accused, but the usual political corruption, too characteristic of the period.

The duties of a commissioner upon the national accounts, did not, however, by any means absorb the whole attention of the indefatigable Lockhart, for while he devoted himself to the service of the pretender, he also proposed a bill in parliament to bestow upon curates the bishops’ rents, to resume all grants of church property that had been made to the universities, which he declared to be public nuisances, mere nests of rebellion, which could not be soon enough annihilated. The service to be accomplished in favour of the exiled family by these measures, is not very clear, and we are prevented from knowing the effect their proposal would have produced, from his friends declining to adopt them. So high, indeed, was he borne by his zeal, that an order was obtained by his friends from St Germains, recommending to him moderate measures, and dissuading him from attempts to openly force the English ministry upon desperate projects, as they were themselves well enough disposed, and were the best judges of the means whereby their good intentions would be carried into effect. This order he dared not disobey, but he owns it was much against his inclination, and takes the liberty of affirming that it injured the pretender’s interest.

On the duke of Hamilton being appointed ambassador to the court of France, he selected the subject of our memoir to wait privately upon him, and to act according to his orders upon an affair of extraordinary moment, which he never explained, but which Lockhart understood to be the pretender’s restoration, and he was just leaving Scotland with the hope of being called to accompany the duke upon that pleasing duty, when he heard that a quarrel betwixt Hamilton and lord Mohun had brought both these distinguished noblemen to an untimely end. This circumstance he affirms to have been fatal to the hopes of the pretender, no one having been found capable of conducting so delicate a business till the period when disputes in the cabinet and the death of the queen rendered the case hopeless. But these circumstances did not damp his ardour, or prevent him from impeding the government, which he could not overturn. Accordingly, on the attempt to extend the malt tax to Scotland, in the year 1713, he made a desperate effort, in which he was seconded by the earls of Mar, Eglinton, Ilay, &c., for the dissolution of the union, a project which narrowly failed of success, as we have narrated more at large in the life of John, duke of Argyle. The attempt to assimilate the Scottish to the English militia which followed, he resisted, and, in his personal friendship, defended the hereditary title of the duke of Argyle to the lieutenancy of the county of Argyle. His friends, who could not see the advantage of such a measure, were displeased, but his design was to bring over the duke to the interests of the Pretender, of which he was always suspicious the ministry were less careful than of their own. He, however, continued to sit and to act with them, under the strongest assurances from Bolingbroke, that every thing he could desire would be done for the Pretender so soon as it was possible to do it with safety, till the prorogation before the death of the queen, when he retired to his residence in the country, and though the same parliament was assembled on the death of the queen, did not attend it, having lost all hope of the Pretender’s restoration by other means than arms.

He accordingly began privately to provide horses and arms for himself and his dependants, though from his late conduct he was not trusted by the leaders of the party to the extent that might have been expected. Nothing, indeed, but mere general surmises seem to have reached him till the month of August, 1715, when warrants were already issued out against all who were suspected as favouring the designs of the earl of Mar, and under one of these warrants he was, early in that month, apprehended at his house of Dryden, and committed prisoner to the castle of Edinburgh. In these circumstances he immediately wrote to the duke of Argyle, who, in return for his services in regard to the militia bill, procured his enlargement, after he had been fifteen days a prisoner, on his giving bail for six thousand merks. He was no sooner liberated than he waited upon his rebel associates, who had not been apprehended; but, finding them still disinclined to the communication, he retired to his house at Carnwath, where he secretly and diligently employed his personal influence in the furtherance of the cause, though still unacknowledged by any of the ostensible leaders of the insurrection, and waited till the arrival of the Pretender, or the transit of the Forth by Mar, should give the signal for him and his friends to appear in arms. In the mean time, a letter from the duke of Argyle informed him that his practices were well known to the government, and requiring him forthwith to repair to his house at Dryden. Every thing, arms, horses, &c., were again disposed of in the best manner that could be devised, and he immediately repaired to Dryden, where he negotiated with Kenmure and the southern rebels; his troop of horse, under the command of his brother Philip Lockhart, being sent to join them at Biggar, he himself staying behind for a few days to arrange some minor concerns. To ensure his safety after concluding his transactions with the rebels, he wrote to the lord justice clerk, requesting to know whether he should remain in Edinburgh or go home to Dryden, and was ordered to choose the latter alternative. Mackintosh, however, having that night crossed the Forth, on his march to the south, a party of soldiers was sent out to Dryden, who apprehended Lockhart, and carried him again to the castle; a circumstance which saved both his life and his estate, as well as those of many others who were prepared to set out with him on an expedition that proved desperate—his whole troop being taken at Preston, along with the rest of their companions, and his brother shot as a deserter by order of a court-martial.

Mr Lockhart suffered a long confinement, but escaped, through the steadiness of his friends, that punishment which was likely to have followed his conduct, and which the government, could they have elicited sufficient evidence, would most willingly have inflicted; but he was by no means cured of his affection for the exiled family, and before two years had elapsed, he was employed as an agent to bring up six thousand bolls of oatmeal, to be given to the king of Sweden as the hire or the reward for his setting the Pretender upon the British throne. Of all the attempts made by the party in its despair, this was certainly the most singular; yet he seems to have embarked in it with that ardour which marked his character, and he contrived to obtain, from the earl of Eglinton, the offer of three thousand guineas towards its accomplishment. It was soon, however, found to be a project which could not be carried into effect. He narrowly escaped being involved in the affair of Glenshiel, and when the Spanish battalion was brought to Edinburgh, he supplied the commander, Don Nicolas, with what money he wanted till he could be supplied with bills from the Spanish ambassador in Holland, telling him, at the same time, that "it was unkind in him to allow himself to be straightened, when he knew the king, for whose cause he suffered, had so many friends in town that would cheerfully assist him."

In 1718, the Pretender commenced a correspondence with Mr Lockhart, which continued with little interruption till l727, when it fell into the hands of the government, by what means has never been fully explained, though most probably it was in consequence of a dispute Mr Lockhart had got into with the episcopal college, respecting the election of a bishop of the name of Gillon, whose ordination was keenly opposed by a number of the presbyters, who objected to the nomination that had been made of him by the Pretender, as unduly influenced by Lockhart, who, for a number of years, had been the only channel through which they communicated with their exiled prince. Many meetings were held, and much rancour displayed on the subject, by the enraged presbyters, who threatened the consequences of the rebellion, in which most of the parties were implicated, if the consecration was persisted in. The bitterness of the disputants made it impossible for them to be secret: the whole came before the public, and the government being masters of the channel of communication, the earliest packet transmitted to Lockhart was waited for, and sent to London. Orders were immediately sent to seize Strahan, a merchant in Leith, to whom the packet had been directed, and, under a strong guard of dragoons, to send him to London. Before setting out, however, he was well instructed how to conduct himself, supplied with money by Lockhart, and the earls of Kincardine and Dundonald, with the assurance, that if he behaved with firmness, nothing could be brought legally home to him, while his family, in the mean time, should be carefully seen to, and he himself would gain honour by the incident. Warrants were at the same time issued for the apprehension of Mr Lockhart and Mr Corsar, one of his friends. The latter was apprehended at Glammis, but the former, taking the alarm, effected his escape into Durham, where he remained in the house of a friend till the 8th of April, when he sailed for Dort, where he arrived in safety. He immediately wrote to the Pretender, through lord Inverness, stating the circumstances into which he had fallen, and that he was waiting his master’s commands before finally resolving how to dispose of himself. In the mean time, he met lord North and Grey at Brussels, who had also been under the necessity of leaving his native country for dabbling in the affairs of the Pretender, and was thus far on his way to the court of that personage, where he hoped to be trusted with the management of his affairs, which, in the hands of colonel Hay and James Murray, (created lords Inverness and Dunbar,) were generally supposed to have fallen into disorder, pressing at the same time that Mr Lockhart should accompany him, and take charge of the affairs of Scotland, while he attended to those of England. Lockhart, however, would not approach the court of the Pretender without his orders, shrewdly suspecting that James was too fond of the lady Inverness, who was lord Dunbar’s sister, to part permanently with either of the three. The lord North and Grey proceeded to his destination, but found, instead of the premiership which he expected, an appointment provided for him in the army of Spain, with which he was obliged to be content. Inverness had been nominally superseded by Sir John Graham, who proposed the most flattering terms to Lockhart; but the former was still first in the Pretender’s affection, and, along with Dunbar, held the entire management of his counsels, which were, and had long been, very far from what the latter gentleman wished. By their advice, and in pursuance of his own feelings, the Pretender no sooner heard of the death of George I. than he left Bologna for Lorrain in the greatest haste, intending to put himself at the head of the Highlanders, and with their assistance, conquer and secure the throne of the three kingdoms; a similar project to that which his son attempted in the year 1745. A messenger was sent to consult Lockhart, who, astonished at the folly of the proposal, assured the Pretender that it would prove the ruin of himself and all his friends, and would deprive him of the power of ever again renewing the attempt. More wise than his son upon a like occasion, he accepted the advice, and returned to Avignon. Lockhart tendered him, afterwards, some long letters, containing very good advices, with which he probably had little hope that he would comply, and learning, in the month of April, 1728, that his friends the duke of Argyle, lord Ilay, and Duncan Forbes, then lord advocate for Scotland, had procured him liberty to return and to live at home unmolested, he embraced the opportunity of doing so, nothing being required of him but his simple promise that he would live in peace. He was, however, required to go by the way of London, and to return thanks personally to George II., who was now in possession of the throne. "This," he says, "did not go well down with me, and was what I would most gladly have avoided, but there was no eviting of it; and as others, whose sincere attachment to the king was never doubted, had often preceded me on such like occasions, I was under the necessity of bowing my knee to Baal, now that I was in the house of Rimmon." Having performed this piece of unwilling submission, he returned to his family in 1728, evidently in despair of furthering the cause in which he had so long exerted himself, and determined to resign all connexion with politics. Of his after history, we have been unable to learn more than that he was slain in a duel on December 17, 1731, having entered the fifty-ninth year of his age.

He was married on the 13th of April, 1697, to Euphemia Montgomery, third daughter of Alexander, ninth earl of Eglinton, by his first wife, Margaret, daughter of William, lord Cochrane, son of the earl of Dundonald. He had seven sons and eight daughters. His eldest son George, possessing somewhat of the prudent foresight of his father, delivered himself up in the year 1746, to Sir John Cope, the day after the battle of Gladsmuir, and was for a considerable time a prisoner at large in England. His grandson George, continued with Charles till after the fatal battle of Culloden, after which he escaped to the continent, and died an exile at Paris some few months before his father, in the year 1761.

As an author, Mr Lockhart is entitled to very considerable praise. His Memoirs concerning the Affairs of Scotland, and his commentaries, though neither so clear nor so impartial as could be wished, are yet valuable materials for history, and throw very considerable light both upon the individual characters and transactions of those times. And his register of letters is still more interesting, as giving us not only an account of the proceedings, but the acts themselves, of the Jacobites of the period. His memoirs were surreptitiously published during his lifetime, by a friend to whom he had lent them, and a key to the names (given in the published volume in initials) was afterwards circulated. He left his papers carefully concealed, with instructions to his heir, to abstain from publishing them till the year 1750; but the connexion of his grandson with the rebellion of 1745 rendering their appearance even then inexpedient, they lay unnoticed until, at the request of count Lockhart, they were edited by Mr Anthony Anfrere in 1817.