and published facsimile publications of historical documents, in which he used his direct access to the archives. In 1820 he became a corresponding member of the Royal Institute of the Netherlands. In 1825 he became a regular member. In 1831, after the death of his mentor Van Wijn, he himself was appointed Rijksarchivaris. In this period he wrote his magnum opus on the history of the Dutch navy: Geschiedenis van het Nederlandsche Zeewezen (6 volumes, between 1833 and 1848). In 1833 he obtained the original copy of the Union of Utrecht treaty for the National Archives from the Koninklijke Bibliotheek, and a large collection of original medieval charters that had previously been held in the Charter room of the County, later Province, of Holland. De Jonge was also politically active. He was appointed a member of the municipal council of The Hague in 1825. In that capacity he became editor of the Dagblad voor Zuid-Holland en 's-Gravenhage (the official publication of the city) in 1827. In 1844 he was elected wethouder (alderman) of The Hague, which he remained till his death. He was also a member of the Provinciale Staten of the province of South Holland between 1840 and 1851. Publications The following is a selection of his published works: Verhalen over den oorsprong der Hoeksche en Kabeljauwsche twisten, (Leiden 1817) Levensschets van Floris den voogd van Holland (1819) Notice sur le Cabinet des médailles et des pierres gravées de S.M. le Roi des Pays-Bas. La Haye (1823) Levensbeschrijving van Johan en Cornelis Evertsen, Luitenant-Admiralen van Zeeland (The Hague 1820) Verhalen over den oorsprong, den voortgang en de hoedanigheid van den invloed des derden Staats in de Statenvergaderingen gedurende het Hertogelijk en Grafelijk bewind in Braband, Vlaanderen, Holland en Zeeland (for which he received a royal gold medal, 1824) De Unie van Brussel des jaars 1577 (The Hague, 1825) Verhandelingen en onuitgegeven stukken, betreffende de geschiedenis der Nederlanden (2 vols., Delft 1825, The Hague 1827) Onderzoek over den oorsprong der Nederlandsche vlag (1831) Hendrik van Wijn als geleerde en staatsman geschetst (1832) Geschiedenis van het Nederlandsche zeewezen (6 vols., The Hague 1833-1848, 2nd edition Haarlem 1858-1862, edited by his son Jan Karel Jacob de Jonge) Neerlands roem ter zee (Zwolle 1868) Nederland en Venetië ('The Hague 1852). References Sources 1793 births 1853 deaths Archivists Aldermen of The Hague 19th-century Dutch historians Dutch numismatists Dutch naval historians Historians of the Netherlands