A ceasefire and a provisional peace agreement between Austria, Prussia and Denmark were signed in Vienna on 1 August 1864. In the agreement, Denmark ceded its rights to Schleswig-Holstein and Lauenburg and transferred them to a joint Austro-Prussian administration. The agreement was confirmed by the Hague Peace Treaty of October 30, 1864. After nearly a year of anger between the two administering powers in the duchy and laborious negotiations, Bismarck succeeded in getting Vienna to reach an agreement on Schleswig-Holstein. On 14 August 1865, Austria and Prussia signed an agreement in Bad Gastein to split the effective management of the duchy, while the unit of joint management of the two duchy was in principle vaguely confirmed (Article 1, 131 CTS 343). While Austria received Holstein, Schleswig returned to Prussia. In addition, Prussia was allowed to buy the Duchy of Lauenburg from Austria, which depended geographically on its own territory. In the meantime, the great powers had begun to take action. Since 24 April 1864, six days after the Battle of Dybbel, a major conference of power had been convened in London.
Although the other three great powers preferred a kind of return to the status quo ante bellum, the Schleswig-Holstein ended up being a secondary vision. When Austria and Prussia increased the stakes at the conference by declaring that they considered the Treaty of London of 1852 to be obsolete, neither other powers showed a great propensity to deny the two German powers, which were now de facto held by the duchy. After Bismarck removed Duke Frederick of Augustenburg from the equation by offering him an impossible agreement that he had duly refused, the path to an Austro-Prussian annexation of the duchy was clear. Sir, I see with some surprise and some regret that the right-wing gentleman, a respected leader on the other side of the house, will move the previous question. I hoped, with the strong opinions I have heard from him on this subject, that he would make a full decision on this Danish question. After asking the government a few questions, I think I have the right to ask Her Majesty`s opposition what it is about foreign policy. If their foreign policy only because the Earl of Malmesbury signed this treaty of 1852 to repair this treaty; If they are prepared, like the noble gentleman from another place, to form a league with France to enforce this treaty against the reluctant duchies, I say that no government, whether taken on this side or on the other side of the house, can hope for the confidence of the people who are ready to plunge this country into a war to that end.