For purposes of historical research he went in 1851 to Sweden, in 1852 to Rome, in 1870 to France, Belgium, and Holland, in 1874 to Russia, a country which he later repeatedly visited.
Between the years 1853 and 1859 he established at Vienna the main historical library of the Teutonic Order.
Dudík was a prolific writer; his works have a lasting value on account of the sources from which he drew.
His chief works in chronological order are: Dudík's most important publication is: "Mährens allgemeine Geschichte" (12 vols., Brünn, 1860–89); it treats the history of Moravia up to 1350.
Volumes VIII-X, which give an account of Moravia during the period of the Przemyslian dynasty, have been translated into Czech.