The period that followed was one, outwardly at least, of political stagnation. The Mainz Commission, though hampered by the jealousy of the governments (the king of Prussia refused to allow his subjects to be haled before it), was none the less effective enough in preventing all free expression of opinion; while at the universities the official "curators" kept Liberal enthusiasts in order. The exuberance of the epoch of Liberation gave place to a dull lethargy in things political, relieved only by the Philhellenism which gave voice to the aspirations of Germany under the disguise of enthusiasm for Greece. Even the July revolution of 1830 in Paris reacted but partially and spasmodically on Germany. In Hanover, Brunswick, Saxony and Hesse-Cassel popular movements led to the granting of constitutions, and in the states already constitutional Liberal concessions were made or promised. But the governments of Prussia and Austria were unaffected; and when the storm had died down Metternich was able, with the aid of the federal diet, to resume his task of holding "the Revolution" in check. No attempt was, indeed, made to restore the deposed duke of Brunswick, who by universal consent had richly deserved his fate; but the elector of Hesse could reckon on the sympathy of the diet in his struggle with the chambers (see HESSE-CASSEL), and when, in 1837, King Ernest Augustus of Hanover inaugurated his reign by restoring the old illiberal constitution abolished in 1831, the diet refused to interfere. It was left to the seven professors of Göttingen to protest; who, deprived of their posts, became as famous in the constitutional history of Germany as the seven bishops in that of England. The Prussian system.