As regards boundary rivers and rivers running through several States, the riparian States[297] can regulate navigation on such parts of these rivers as they own, and they can certainly exclude vessels of non-riparian States altogether unless prevented therefrom by virtue of special treaties.
Navigation on International Rivers.
§ 178. Whereas there is certainly no recognised principle of free navigation on national, boundary, and not-national rivers, a movement for the recognition of free navigation on international rivers set in at the beginning of the nineteenth century. Until the French Revolution towards the end of the eighteenth century, the riparian States of such rivers as are now called international rivers could, in the absence of special treaties, exclude foreign vessels altogether from those parts of the rivers which run through their territory, or admit them under discretionary conditions. Thus, the river Scheldt was wholly shut up in favour of the Netherlands according to article 14 of the Peace Treaty of Munster of 1648 between the Netherlands and Spain. The development of things in the contrary direction begins with a Decree of the French Convention, dated November 16, 1792, which opens the rivers Scheldt and Meuse to the vessels of all riparian States. But it was not until the Vienna Congress[298] in 1815 that the principle of free navigation on the international rivers of Europe by merchantmen of not only the riparian but of all States was proclaimed. The Congress itself realised theoretically that principle in making arrangements[299] for free navigation on the rivers Scheldt, Meuse, Rhine, and on the navigable tributaries of the latter—namely, the rivers Neckar, Maine, and Moselle—although more than fifty years elapsed before the principle became realised in practice.
[298] Articles 108-117 of the Final Act of the Vienna Congress; see Martens, N.R. II. p. 427.
[299] "Règlements pour la libre navigation des rivières"; see Martens, N.R. II. p. 434.
The next step was taken by the Peace Treaty of Paris of 1856, which by its article 15[300] stipulated free navigation on the Danube and expressly declared the principle of the Vienna Congress regarding free navigation on international rivers for merchantmen of all nations as a part of "European Public Law." A special international organ for the regulation of navigation on the Danube was created, the so-called European Danube Commission.
[300] See Martens, N.R.G. XV. p. 776. The documents concerning navigation on the Danube are collected by Sturdza, "Recueil de documents relatifs à la liberté de navigation du Danube" (Berlin, 1904).
A further development took place at the Congo Conference at Berlin in 1884-85, since the General Act[301] of this Conference stipulated free navigation on the rivers Congo and Niger and their tributaries, and created the so-called "International Congo Commission" as a special international organ for the regulation of the navigation of the said rivers.
[301] See Martens, N.R.G. 2nd Ser. X. p. 417.