Russia in her turn had to conciliate the Porte, Sweden, Persia, and Great Britain. The Turkish negotiations were prolonged, and it was only in May that the treaty of Bucharest was signed, by which Russia gave up all her conquests except Bessarabia. Sweden had offered Russia her alliance in February. She was prepared to surrender Finland to Russia on condition that Russia should assist her in the conquest of Norway. A joint army was to effect this conquest and then make a descent on North Germany, threatening the rear of the French army of invasion. The adhesion of Great Britain was to be invited. On April 5 an alliance between Russia and Sweden was signed on the terms suggested. This was followed on August 28 by the treaty of Åbo, which was signed in the presence of the British representative, Lord Cathcart. By this treaty Russia was to assist Sweden with 30,000 men and a loan, Sweden undertook to support Russia's claim, when it should be made, for an extension of her frontier to the Vistula. Shortly afterwards it was agreed to postpone the attack on Norway till the following year, and thus at length the Russian army in Finland was set free. The treaties with the Porte and Sweden were too late to liberate troops to oppose Napoleon's advance, but the troops thus liberated greatly endangered his retreat. With Persia no peace could be made. Great Britain was still nominally at war both with Russia and with Sweden. Negotiations with Russia in April came to nothing because the British government refused to take over a loan of £4,000,000, but on July 18 a treaty of alliance between the three powers was signed, in which Great Britain promised pecuniary aid to Russia. A further sign of friendship was given when the tsar handed over the Cronstadt fleet for safekeeping to the British. The formal treaty was, however, only the public recognition of a friendship and mutual confidence which had begun with the breach between Russia and France. This good understanding was shared by the nominal allies of France, Prussia and Austria. Russia was fully informed of the military and political plans of Austria, and knew that her forces would not fight except under compulsion.