Read it through once

But though Russell was no more, there were not wanting, either in the provinces through which the duke passed, or in other parts of the kingdom, many noble and wealthy families who were attached to the principles of the Whigs. To account for their neutrality, and, if possible, to persuade them to a different conduct, was naturally among his principal concerns. Their present coldness might be imputed to the indistinctness of his declarations with respect to what was intended to be the future government. Men zealous for monarchy might not choose to embark without some certain pledge that their favourite form should be preserved. They would also expect to be satisfied with respect to the person whom their arms, if successful, were to place upon the throne. To promise, therefore, the continuance of a monarchical establishment, and to designate the future monarch, seemed to be necessary for the purpose of acquiring aristocratical support. Whatever might be the intrinsic weight of this argument, it easily made its way with Monmouth in his present situation. The aspiring temper of mind which is the natural consequence of popular favour and success, produced in him a disposition to listen to any suggestion which tended to his elevation and aggrandisement; and when he could persuade himself, upon reasons specious at least, that the measures which would most gratify his aspiring desires would be, at the same time, a stroke of the soundest policy, it is not to be wondered at that it was immediately and impatiently adopted. Urged, therefore, by these mixed motives, he declared himself king, and issued divers proclamations in the royal style; assigning to those whose approbation he doubted the reasons above adverted to, and proscribing and threatening with the punishment due to rebellion such as should resist his mandates, and adhere to the usurping Duke of York.