The Anglo-Russian invasion of Holland started well, with a British victory - the Battle of Callantsoog (27 August 1799) - in the north, but when the Russian army arrived in September, the allies found themselves faced with bad weather, poor coordination, and unexpectedly fierce resistance from the Dutch and the French, and their success evaporated. As the month wore on, the weather worsened and the allies suffered more and more losses, eventually signing an armistice in October 1799. The Russians suffered three-quarters of allied losses and the British left the Russian troops on an island in the Channel after the retreat, as Britain did not want them on the mainland. This defeat and subsequent maltreating of Russian troops strained Russo-British relations, but a definitive break did not occur until later. The reasons for this break are less clear and simple than those of the split with Austria, but several key events occurred over the winter of 1799–1800 that helped: Bonaparte released 7,000 captive Russian troops that Britain had refused to pay the ransom for; Paul grew closer to the Scandinavian countries of Denmark and Sweden, whose claim to neutral shipping rights offended Britain; Paul had the British ambassador in St. Petersburg (Whitworth) recalled (1800) and Britain did not replace him, without any clear reason given as to why; and Britain, needing to choose between their two allies, chose Austria, who had with certainty committed to fighting the French to the end.