In August 1791 Leopold had met Frederick William II of Prussia at Pillnitz Castle near Dresden, and the two monarchs had joined in stating in the Declaration of Pillnitz that they considered the restoration of order and of monarchy in France an object of interest to all sovereigns. They further declared that they would be ready to act for this purpose in concert with the other powers. Montague (1911) argued that this declaration appeared to have been drawn from Leopold by pressure of circumstances. Leopold well knew that concerted action of the powers was impossible, as Great Britain had firmly resolved not to meddle with French affairs. After Louis had accepted the constitution, Leopold virtually withdrew his declaration. Nevertheless, it remained a grave error of judgment and contributed to the approaching war.