The violent language of the liberal party, especially at the universities, already began to terrify the Prussian government. The first danger signal was given at the Wartburg festival of delegates from the German universities in 1817, at which the students indulged in some boyish manifestations of their sympathies; their proceedings made some stir in Germany, and Metternich declared that they were revolutionary. The horror of liberalism was destined to be heightened in 1819 by the murder of the tsar's agent, the dramatist Kotzebue, by a lunatic member of a political society at Giessen. Its immediate result was a conference of German ministers at Carlsbad, where several resolutions for the suppression of political agitation were passed, and afterwards adopted by the diet at Frankfort. This policy was embodied in the "final act" of a similar conference held at Vienna in the following year (1820), which empowered the greater states of Germany to aid the smaller in checking revolutionary movements. At the same time it reaffirmed the general principle of non-intervention, and even laid down the pregnant doctrine that constitutions could not be legitimately altered except by constitutional means. The union of Austria and Prussia on the conservative side had rather the effect of throwing the secondary states of southern Germany upon the liberal side. In the spring and summer of 1818 Bavaria and Baden framed constitutions, and in 1819 Würtemberg once more essayed parliamentary government, which the reactionary policy of her first parliament had compelled her to abandon. The significant fact in European politics was that Frederick William III. of Prussia, always accustomed to being led, had passed from the influence of Russia to that of Austria. [Pageheading: _THE CONFERENCE OF AIX-LA-CHAPELLE._]