The
Fourth Coalition against
Napoleon's
French Empire was defeated in a war spanning 1806–1807. Coalition partners included
Prussia,
Russia,
Saxony,
Sweden, and
Great Britain. Several members of the coalition had previously been fighting France as part of the
Third Coalition, and there was no intervening period of general peace. On 9 October 1806, Prussia joined a renewed coalition, fearing the rise in French power after the defeat of
Austria and establishment of the French-sponsored
Confederation of the Rhine. Prussia and Russia mobilized for a fresh campaign, and Prussian troops massed in Saxony.