In 1824, having obtained formal license to assume the surname of Alexander, he procured himself to be served “lawful and nearest heir-male in general of the body of the said Hannah Alexander,” before the bailies of Canongate, 1826.  Then he assumed the title of Earl of Stirling and Dovan, and, in 1830, formally registered himself as “lawful and nearest heir in general to the deceased William, the first Earl of Stirling.”

According to the patent of 1633, which was confined to heirs-male, Humphreys had no claim either to the title or estates; but he based his pretensions upon a document which, he said, had been granted by Charles I., in 1639, to the Earl of Stirling, and which conferred upon him, without limitation as to issue, the whole estates in Scotland and America, as well as the honours conveyed by the original patent.  This he attempted to prove in an action in the Court of Session, which was dismissed in 1830, as was also a similar action for a like purpose in 1833.

But, although not officially recognised, he assumed all the imaginary privileges of his position, granting to his friends vast districts of Canadian soil, creating Nova-Scotian baronets at his own discretion, and acting, if not like a king, at least like a feudal magnate of the first degree.  He caused notice after notice to be issued proclaiming his rights, and the records of the time are filled with strange proclamations and announcements, to which his name is attached.  As a rule, these productions are far too lengthy to be copied, and far too involved to be readily summarized.  They have all a lamentably commercial tone, and invariably exhibit an unworthy disposition to sacrifice great prospective or assumed advantages for a very little ready money.  Take, for instance, his address to the public authorities of Nova Scotia, issued in 1831.  In it, after informing his readers of the steps which he had taken to assert his rights, and the prospects which existed of their recognition, he hastens to observe that “persons desirous of settling on any of the waste lands, either by purchase or lease, will find me ready to treat with them on the most liberal terms and conditions;” and throws out a gentle hint that in any official appointment he might have to make, he would prefer that “the persons to fill them should rather be Nova Scotians or Canadians, than the strangers of England.”  At the same time he issued numerous advertisements in the journals, reminding all whom it might concern of his hereditary rights, and warning the world in general against infringing his exclusive privileges.  At length, having succeeded in gaining notoriety for himself, he aroused the Scotch nobility.  On the 19th of March 1832, the Earl of Rosebery proposed and obtained a select committee of the House of Lords, with a view of impeding “the facility with which persons can assume a title without authority, and thus lessen the character and respectability of the peerage in the eyes of the public;” and the Marchioness of Downshire, the female representative of the house of Stirling, forwarded a petition to the Lords, complaining of the undue assumption of the title by Mr. Humphreys.