[1] At around 55BC, the time of Julius Caesar, the territories west of the Rhine in this region were occupied by the Eburones, one of the tribes he identified as "Germani cisrhenani", who lived within the part of Gaul associated with the Belgae.
However, Tacitus reported that "Tungri" was a new name for the original "Germani", stating that in fact the first tribal group to be called by that name were the ones from west of the Rhine.
The Cugerni, who lived in the "Civitas Traiana" near Xanten during imperial times, are often thought to be Sugambri who had been resettled by the Romans west of the Rhine.
East of the Rhine, Roman historians such as Tacitus report that to the north of the Sugambri were also the Bructeri, who pushed further south into the Sugambrian area during imperial times, under pressure from their northern neighbours the Chamavi and Angrivarii.
By late Roman times it appears that whatever remained of these tribal groupings began to be referred to as the Franks, who were being pressed from the North by the Saxons.
As the central power of the Holy Roman Emperor weakened, the Rhineland split up into numerous small independent principalities, each with its separate vicissitudes and special chronicles.
In spite of its dismembered condition, and the sufferings it underwent at the hands of its French neighbours in various periods of warfare, the Rhenish territory prospered greatly and stood in the foremost rank of German culture and progress.
After the defeat of the Prussian Army at the Battle of Jena-Auerstedt, the Treaty of Tilsit in 1807 made the Westphalian territories part of the Kingdom of Westphalia from 1807 to 1813.
After the Congress of Vienna, the Kingdom of Prussia received a large amount of territory in the Westphalian region and created the province of Westphalia in 1815.
Prussia first set foot on the Rhine in 1609 by the occupation of the Duchy of Cleves and about a century later Upper Guelders and Moers also became Prussian.
The congress of Vienna assigned the whole of the lower Rhenish districts to Prussia, which had the tact to leave them in undisturbed possession of the liberal institutions they had become accustomed to under the republican rule of the French.
[3] During the late 19th century the region developed into the center of the German steel industry, whose products were shipped and used in construction worldwide.
In 1920, the Saar was separated from the Rhine Province and administered by the League of Nations until a plebiscite in 1935, when the region was returned to the German Reich.