By the time the revolutionary movement in Europe had begun to break out in various cities, the
monarchist and restorationist secretary to the Dutch king began lecturing on the spiritual-political crisis of the Continent. Groen also was ready to publish. He had begun to do so with his
Overview of 1831, his
Essay on Truth of 1834, a manuscript harder to date precisely but entitled
Studies on the revolution, his
Prolegomena of 1847 (the following year
Karl Marx issued the
Communist Manifesto). Groen's most influential work
Lectures on Unbelief and Revolution appeared in an initial edition in 1847, and then a revised edition of 1868; there were subsequent editions as well. In time he founded an intellectual Christian political circle among the upper classes, through which Groen tried to teach the political responsibility of such people. In an effort to reach the Dutch intellectuals, he founded the daily newspaper De Nederlander from 1850 until 1855. Later on 1896, he published the weekly Nederlandsche Gedachten (Dutch Thoughts/Reflections). He is best known as the editor of the ''Archives et correspondence de la maison d'Orange'' (12 vols, 1835-1845), which procured for him the title of the Dutch
Gachard.
John L. Motley acknowledges his indebtedness to Groen's
Archives in the preface to his
Rise of the Dutch Republic, at a time when the American historian had not yet made the acquaintance of King William's archivist. It also bore testimony to Groen's influence as a writer of history in the correspondence published after his death. At the first reception, in 1858, of Motley at the royal palace at the Hague, the king presented him with a copy of Groen's
Archives as a token of appreciation and admiration of the work done by of William I, prince of Orange. This copy, bearing the king's autograph inscription, afterwards came into the possession of
Sir William Vernon Harcourt, Motley's son-in-law. ==Thoughts==