After peace was concluded, not only the Orange partisans but the great mass of the people, who had so long been excluded from all share of political power, desired a drastic reform of the government.  They had conferred sovereign authority upon William, and would have willingly increased it, in the hope that he would in his person be a centre of unity to the State, and would use his power for the sweeping away of abuses.  It was a vain hope.  He never attempted to do away, root and branch, with the corrupt municipal oligarchies, but only to make them more tolerable by the infusion of a certain amount of new blood.

The birth of an heir on March 8,1748, caused great rejoicings, for it promised permanence to the new order of things.  Whatever the prince had firmly taken in hand would have met with popular approval, but William had little power of initiative or firmness of principle.  He allowed his course of action to be swayed now by one set of advisers, now by their opponents.  Even in the matter of the farmers of the revenue, the best-hated men throughout the Republic and especially in Holland, it required popular tumults and riots at Haarlem, Leyden, the Hague and Amsterdam, in which the houses of the obnoxious officials were attacked and sacked, to secure the abolition of a system by which the proceeds of taxation were diverted from the service of the State to fill the pockets of venal and corrupt officials.  In Amsterdam the spirit of revolt against the domination of the Town Council by a few patrician families led to serious disorders and armed conflicts in which blood was shed; and in September, 1748, the prince, at the request of the Estates, visited the turbulent city.  As the Town Council proved obstinate in refusing to make concessions, the stadholder was compelled to take strong action.  The Council was dismissed from office, but here, as elsewhere, the prince was averse from making a drastic purge; out of the thirty-six members, more than half, nineteen, were restored.  The new men, who thus took their seats in the Town Council, obtained the sobriquet of “Forty-Eighters.”

The state of both the army and navy was deplorable at the end of the war in which the States had played so inglorious a part.  William had neither the training nor the knowledge to undertake their reorganisation.  He therefore sought the help of Lewis Ernest, Duke of Brunswick-Wolfenbuettel (1718-86), who, as an Austrian field-marshal, had distinguished himself in the war.  Brunswick was with difficulty persuaded, in October, 1749, to accept the post of Dutch field-marshal, a salary of 60,000 fl. being guaranteed to him, the governorship of Hertogenbosch, and the right to retain his rank in the Austrian army.  The duke did not actually arrive in Holland and take up his duties until December, 1750.