Editing Franco-Prussian War (section)

===Occupation of Saarbrücken===
{{main|Battle of Saarbrücken}}
[[File:Franco-Prussian-War Phase 1 toSedan.svg|thumb|upright=1.7|Course of the first phase of the war up to the [[Battle of Sedan]] on 1 September 1870]]
Napoleon III was under substantial domestic pressure to launch an offensive before the full might of Moltke's forces was mobilized and deployed. Reconnaissance by Frossard's forces had identified only the [[16th Division (German Empire)|Prussian 16th Infantry Division]] guarding the border town of [[Saarbrücken#19th century|Saarbrücken]], right before the entire Army of the Rhine. Accordingly, on 31 July the Army marched forward toward the [[Saar River]] to seize Saarbrücken.{{sfn|Wawro|2003|pp=85–86, 90}}

General Frossard's II Corps and Marshal Bazaine's III Corps crossed the German border on 2 August, and began to force the Prussian 40th Regiment of the [[16th Division (German Empire)|16th Infantry Division]] from the town of Saarbrücken with a series of direct attacks. The Chassepot rifle proved its worth against the [[Needle gun|Dreyse rifle]], with French riflemen regularly outdistancing their Prussian counterparts in the skirmishing around Saarbrücken. However the Prussians resisted strongly, and the French suffered 86 casualties to the Prussian 83 casualties. Saarbrücken also proved to be a major obstacle in terms of logistics. Only one railway there led to the German hinterland but could be easily defended by a single force, and the only river systems in the region ran along the border instead of inland.{{sfn|Wawro|2003|pp=87, 90}} While the French hailed the invasion as the first step towards the Rhineland and later Berlin, General [[Edmond Le Bœuf]] and Napoleon III were receiving alarming reports from foreign news sources of Prussian and Bavarian armies massing to the southeast in addition to the forces to the north and northeast.{{sfn|Wawro|2003|p=94}}

Moltke had indeed massed three armies in the area—the Prussian First Army with 50,000 men, commanded by [[Karl Friedrich von Steinmetz|General Karl von Steinmetz]] opposite [[Saarlouis]], the Prussian Second Army with 134,000 men commanded by [[Prince Friedrich Karl of Prussia (1828–1885)|Prince Friedrich Karl]] opposite the line [[Forbach]]-[[Battle of Spicheren|Spicheren]], and the Prussian Third Army with 120,000 men commanded by Crown Prince [[Friedrich III, German Emperor|Friedrich Wilhelm]], poised to cross the border at Wissembourg.{{sfn|Howard|1991|p=82}}