February 8, Napoleon fought the desperate battle of Eylau, which closely resembled a defeat. His position was critical; but before Canning could fairly get control of events, Napoleon, June 14, again attacked the Russians at Friedland and won a decisive victory. June 25 Napoleon and Alexander held an interview on an island in the Niemen. The chief point in question was whether Alexander would abandon England; and this he was almost glad to do, for England had abandoned him. Alexander yielded to the force and flattery of Napoleon, and signed July 7 the treaty of Tilsit. By a private understanding the remaining neutrals were left to Napoleon to be dealt with as he pleased. Denmark was the only neutral power the control of which was necessary for the success of Napoleon’s system, and August 2 he sent orders to Bernadotte, who was to command at Hamburg: “If England does not accept the mediation of Russia, Denmark must declare war upon her, or I will declare war on Denmark.”[40] Finding that the Prince Royal hesitated, Napoleon, August 17, sent orders[41] to Bernadotte to hold himself ready with all his troops to march into Denmark either as ally or enemy, according to the issue of the pending negotiation. Threatened by this overwhelming danger, the Prince Royal of Denmark alternately promised and evaded the declaration of war; when suddenly his doubts were brought to an end by the diplomacy of Canning. The British ministry had been secretly informed of what took place at Tilsit, and even without secret information could not have doubted the fate of Denmark. Vigor was necessary; and as early as July 19, before news had arrived of the formal signature of the Tilsit treaty, the Cabinet decided on sending to Copenhagen a large naval expedition which had been collected for a different purpose. July 26 the expedition, commanded by Lord Gambier, sailed from the Downs. It consisted of some twenty ships of the line, forty frigates, and transports containing twenty-seven thousand troops commanded by Lord Cathcart; and it carried a diplomatic agent with instructions to require from the Prince Royal of Denmark the delivery of the Danish fleet, as a temporary security for the safety of England.