The immediate objective of General Tann's new “Army Section” – a Bavarian corps, a Prussian infantry division and two Prussian cavalry divisions – was to find and destroy the French XV Corps under General Joseph La Motterouge. Ordered by War Minister Leflô to “do something for the sake of public opinion,” La Motterouge had drawn in his brigades from Vierzon, Bourges, and Nevers and concentrated them at Orléans. Sent south by Moltke to preempt threats like this and “clear the country between Paris and the Loire,” Tann left Etampes with five divisions in early October.

Marching and eating well in the flat, gold-stubbled Beauce, the Germans made good time. Each cross road that ought to have been held by the French was either deserted or lightly defended, allowing the Germans to punch through easily using their cavalry and guns to maximum advantage on plains so flat and featureless that, as one veteran put it, “the earth and sky swam together before your eyes.” With most of France's regular army in captivity, the Germans collided with a strange soldatesca, including francs-tireurs (irregular “sharpshooters”) and new formations of “partisans.” Because the Germans were summarily executing francs-tireurs – depressing morale among would-be guerrillas – the government at Tours had created semi-official partisan companies that carried government pay books and wore uniforms, albeit outlandish ones. The Partisans de Gers, encountered by the Prussians at Etampes, wore long black coats, black trousers, red scarves, and broad-brimmed Calabrian hats.