Daybreak on February 8 sees forty-four thousand five hundred  French troops on the field against sixty-seven thousand Russians, but after receiving reinforcements the French had seventy-five thousand men against seventy-six thousand.

Napoleon hopes to pin Bennigsen's army long enough to allow Ney's and Davout's troops to outflank the Russians.

A fierce struggle ensues, made worse by a blinding snowstorm on the battlefield.

The French find themselves in dire straits until a massed cavalry charge, made by ten thousand seven hundred troopers formed in eighty squadrons, relieves the pressure on the center.

Davout's arrival means the attack on the Russian left can commence, but the assault is blunted when a Prussian force under Lestoq suddenly appears on the battlefield and, with Russian help, throws the French back.

Ney comes too late to effect any meaningful decision, so Bennigsen retreats.

After fourteen hours of continuous battle, there is still no result but enormous loss of life.

Casualties at this indecisive battle are horrific, perhaps twenty-five thousand on each side.

More importantly, however, the lack of a decisive victory by either side means that the war will go on

Authors differ greatly in their assessments of the relative losses: estimates of Russian casualties range from about fifteen thousand to twenty thousand killed or wounded and three thousand soldiers, twenty-three cannon and sixteen colors captured.

Count von Bennigsen estimates his losses at up to nine thousand dead and seven thousand wounded.

The French lose somewhere between ten thousand to fifteen thousand and twenty-five thousand to thirty thousand, with five Eagles lost.

The French have gained possession of the battlefield—nothing but a vast expanse of bloodstained snow and frozen corpses—but they have suffered enormous losses and failed to destroy the Russian army.

The inconclusive Battle of Eylau is a major contrast to the decisive victories that had characterized Napoleon's earlier campaigns.

By halting the French advance and leaving the two sides exhausted but evenly matched, it serves only to prolong the war.