Treaties of Tilsit

The Fourth Coalition came dear: Eylau, on 8 February 1807, ended in the snow in a slaughter without a victor. Only Friedland, on 14 June, broke Bennigsen's army. Alexander I, abandoned by an exhausted Prussia and disappointed by English subsidies, asked for a meeting.

On 25 June the two emperors met alone on a canopied raft moored in the middle of the Niemen at Tilsit. Frederick William III waited on the bank, in the rain. A fortnight of festivities and conversation sealed an alliance: Alexander recognised every French conquest and joined the Continental System; Napoleon left him a free hand against Sweden and Turkey.

Prussia paid for everyone: stripped of half its territory and population, it lost its Polish provinces, which formed the Grand Duchy of Warsaw, and everything west of the Elbe, given to the new Kingdom of Westphalia entrusted to Jérôme Bonaparte. It endured a crushing occupation and indemnity.

Tilsit marked the diplomatic summit of the Empire: two emperors dividing a continent. But the Grand Duchy of Warsaw alarmed Saint Petersburg, the blockade ruined Russian trade, and the alliance would unravel in five years — until the Niemen of 1812, crossed this time in the opposite direction.