The River Rhine has been the most important European trade artery during the industrial period. It is now a commercial navigation between Rotterdam and Basle. Its course through the Netherlands has been much changed over the centuries, and between Basle and Strasbourg it is paralled by the Grand Canal de l’Alsace. Removal of the many tolls on the river was begun in 1815 by the Treaty of Vienna which established the Central Commission for Navigation on the Rhine, which met for the first time in Mainz in 1816, moved to Mannheim in 1861, and to Strasbourg in 1920.
The first steamboat on the river, the British Defiance, reached Cologne in 1816, and the following year the Caledonia, commanded by the son of James Watt, reached Koblenz. In 1826 the forerunner of the Koln-Dusseldorfer Rheinschiffart company established a passenger service which proved popular as a route to Switzerland.
The river was notable for the huge floats of timber that passed from its upper reaches to the shipyards of the Netherlands, but the opening of railways reduced freight carrying, and by 1855 the head of commercial navigation was effectively Mannheim. The channel was improved under the direction of Colonel Gottfried von Tulla, to Strasbourg in 1876, and then to Basle, where the first train of barges arrived in 1904. On other stretches the channel was deepended with the aid of explosives in the mid-nineteenth century. Traffic levels grew substantially in the 20th century, and barge traffic remains heavy.
The most scenically attractive stretch of the river, the series of gorges between Koblenz and Rüdesheim, was inscribed as a UNESCO World Heritage Site in 2002. For much of its length the Rhine can be viewed from the railways that pass along its banks, or on foot or bicycle from towpaths. The Koln-Dusseldorfer Rheinschiffart operates daily scheduled passenger services between Cologne and Mainz, and the river between the Netherlands and Basle, as well as its tributaries the Main and the Moselle, can be experienced by cruise ships operated by several companies.