Although Frederick William had refused to become emperor, he was unwilling to miss altogether the opportunity afforded by the difficulties of Austria. He invited the states to send representatives to Berlin to discuss the condition of Germany; and he concluded a treaty with the kings of Saxony and Hanover. Two days afterwards the three allies agreed upon a constitution which was in many respects identical with that drawn up by the Frankfort parliament. The functions of the executive were, however, extended, the electoral law was made less democratic, and it was decided that, instead of an emperor, there should be merely a supreme chief aided by a college of princes. This constitution was accepted by a number of states, which assumed the name of "The Union," and on the 20th of March 1850 a parliament consisting of two houses met in Erfurt. Both houses accepted the constitution; and, immediately after they broke up, the members of the Union assembled in Berlin, and a provisional college of princes was elected. By that time, however, the whole situation of Germany had changed. In the autumn of 1849 Austria had succeeded, by the help of Russia, in quelling the Hungarian insurrection, and she was then in no mood to let herself be thrust aside by Prussia. Encouraged by her, Hanover and Saxony had severed themselves from the Union, and Saxony, Württemberg and Bavaria arrived at an understanding as to a wholly new constitution. Afterwards all four states, with several others, accepted the invitation of Austria to consider the propriety of re-establishing the Confederation. The representatives of the states favourable to this proposal, i.e. Austria, Luxemburg, Denmark and the four kingdoms, came together in Frankfort on the 4th of September 1850, constituted themselves a _Plenum_ of the old diet and refused to admit the other states except under the terms of the act of 1815. Disturbance in Hesse-Cassel.