Rhine River in the context of "Bundesautobahn 57"

Alsace–Lorraine (German: Elsaß–Lothringen), officially the Imperial Territory of Alsace–Lorraine (German: Reichsland Elsaß–Lothringen), was a territory of the German Empire which is now part of France. It was established in 1871 by the German Empire after it had occupied the region during the Franco-Prussian War. The region was officially ceded to the German Empire in the Treaty of Frankfurt. French resentment about the loss of the territory was one of the contributing factors to World War I. Alsace–Lorraine was annexed in practice by France at the war's end following Germany's defeat in 1918, but only formally ceded back in 1920 as part of the Treaty of Versailles.

Geographically, Alsace–Lorraine encompassed most of Alsace and the Moselle department of Lorraine; the Alsatian part lay in the Rhine Valley on the west bank of the Rhine River, east of the Vosges Mountains, while the section initially in Lorraine was in the upper Moselle valley to the north of the Vosges. Politically, it was the only subdivision of the German Empire considered an "Imperial Territory"; as such, it was under the direct administration of the Imperial German state, rather than a quasi-sovereign constituent of the federal Empire. It was granted a legislature and limited internal autonomy in 1911.

The Western Allied invasion of Germany was coordinated by the Western Allies during the final months of hostilities in the European theatre of World War II. In preparation for the Allied invasion of Germany east of the Rhine, a series of offensive operations were designed to seize and capture its east and west banks: Operation Veritable and Operation Grenade in February 1945, and Operation Lumberjack and Operation Undertone in March 1945; these are considered separate from the main invasion operation. The Allied invasion of Germany east of the Rhine started with the Western Allies crossing the river on 22 March 1945 before fanning out and overrunning all of western Germany from the Baltic in the north to the Alpine passes in the south, where they linked up with troops of the U.S. Fifth Army in Italy. Combined with the capture of Berchtesgaden, any hope of Nazi leadership continuing to wage war from a so-called "national redoubt" or escape through the Alps was crushed, shortly followed by unconditional German surrender on 8 May 1945. This is known as the Central Europe Campaign in United States military histories.

By early 1945, events favored the Allied forces in Europe. On the Western Front, the Allies had been fighting in Germany with campaigns against the Siegfried Line since the Battle of Aachen, the Battle of Metz and the Battle of Hürtgen Forest in late 1944 and by January 1945, had pushed the Germans back to their starting points during the Battle of the Bulge. The failure of this offensive exhausted Germany's strategic reserve, leaving it ill-prepared to resist the final Allied campaigns in Europe. Additional losses in the Rhineland further weakened the German Army, leaving shattered remnants of units to defend the east bank of the Rhine. On 7 March, the Allies seized the intact bridge across the Rhine at Remagen, and established a large bridgehead on the river's east bank. During Operation Lumberjack, Operation Plunder and Operation Undertone, German casualties during February–March 1945 are estimated at 400,000 men, including 280,000 men captured as prisoners of war.

Brandenburg–Prussia (German: Brandenburg-Preußen; Low German: Brannenborg-Preußen) is the historiographic denomination for the early modern realm of the Brandenburgian Royal dynasty of the House of Hohenzollern between 1618 and 1701. Based in the Electorate of Brandenburg, the main branch of the Hohenzollern intermarried with the branch ruling the Duchy of Prussia, and secured succession upon the latter's extinction in the male line in 1618.

Another consequence of the intermarriage between the nobility was the acquisition / incorporation of the lands far to the west of Brandenburg–Prussia located in western Germany of the Holy Roman Empire (A.D. c. 800 / 962 to 1806), and situated in the lower Rhenish / Rhine River of the principalities of the Duchy of Cleves, County of Mark and County of Ravensberg after the signing and agreements in the Treaty of Xanten in 1614.

Operation Lumberjack was a military operation with the goal of capturing the west bank of the Rhine River and seizing key German cities, near the end of World War II in Europe. The First United States Army launched the operation in March 1945 to capture strategic cities in Nazi Germany and to give the Allies a foothold along the Rhine.

One unexpected outcome was the capture of the Ludendorff bridge, a strategic railroad bridge across the Rhine, in the Battle of Remagen. Despite German attempts to destroy the bridge, Allied forces captured it intact and were able to use it along with pontoon and treadway bridges to establish a bridgehead. The bridge finally collapsed at 3:00 PM on 17 March 1945 after ten days of aircraft bombing, direct artillery hits, near misses, and demolition attempts.