led a vanguard further across the frozen sea that on 19 March reached the Swedish shore within 70 km from Stockholm. When news of Kulnev's incursion spread to the Swedish capital, the new king sent an embassy to Knorring, proposing a truce. The Russian commander agreed and speedily recalled Kulnev back to Åland. Meanwhile, the other Russian contingent—5,000 men under Barclay de Tolly—endured great hardship in crossing the frozen gulf further north; they entered Umeå on 24 March. The third force, commanded by Count Shuvalov, struck against Torneå and, braving fierce frost, encircled a Swedish army, which capitulated on 25 March. Six days later, the czar arrived in Åbo and, on learning about the truce, not only revoked Knorring's signature but named Barclay de Tolly as the new Commander-in-Chief. Hostilities thus continued until May, when Shuvalov finally reached Umeå, where he was succeeded by Kamensky. Summer 1809 and conclusion A British Royal Navy fleet under Admiral James Saumarez had arrived in Sweden in May and he concentrated his ships, 10 ship of the line and 17 smaller ships, to the Gulf of Finland. The presence of the British naval units kept the Russian battlefleet strictly confined to Kronstadt, and after the British constructed artillery batteries to the Porkkala cape they cut off the coastal sea route from Russian ships. Total British control of the Gulf of Finland was a large obstacle to the Russian supply network and required sizable garrisons to be posted all along the Finnish coast. The Royal Navy captured 35 Russian ships and burnt 20 others before leaving the Baltic Sea on 28 September 1809. In August, Charles XIII, anxious to improve his position at a peace settlement, ordered General Gustav Wachtmeister to land in the north of Sweden and to attack Kamensky's rear. Engagements at Sävar and Ratan proved inconclusive and Kamensky succeeded in neutralizing this belated counter-offensive, following up with a final victory over the Swedes at Piteå. Wachtmeister's action was only a prelude to the peace negotiations that opened in August and resulted in the Treaty of Fredrikshamn (17 September), in which Sweden ceded the whole of Finland and all of its domains east of the Torne River (the north-eastern parts of what was then called Västerbotten, today Norrbotten) to Russia. Sweden then joined the Continental System and closed its harbours to British ships, leading to a formal declaration of war on Great Britain.