As one of the suite of an embassy he passed through Livonia and Germany till he arrived at Amsterdam, where he worked as a hand at shipbuilding. He also studied surgery at this time, and incidentally paid a visit to William of Orange at The Hague. Early next year he visited England, formally, lodging at Deptford, and continuing his training in naval construction. Thence, and from Holland, he collected mathematicians, engineers, and skilled workmen. Finally, he returned to Russia by way of Vienna, to establish satisfactory relations with the emperor, his natural and necessary ally against the Turk. Peter had made his arrangements for Russia during his absence. Gordon with his corps was at Moscow; the Strelitz were distributed in Astrakan and Azov, where some successful operations were carried out. Nevertheless, sedition raised its head. Insurrection was checked by Gordon, but disaffection remained. Reappearing unexpectedly, he punished the mutinous Strelitz mercilessly, and that body was entirely done away with. New regiments were created on the German model; and he then set about reorganising the finances, reforming the political position of the Church, destroying the power of the higher clergy, and generally introducing more enlightened customs from western Europe. _III.--War with Sweden_ In 1699, the sultan was obliged to conclude a peace at Carlovitz, to the advantage of all the powers with whom he had been at war. This set Peter free on the side of Sweden. The youth of Charles XII. tempted Peter to the recovery of the Baltic provinces. He set about the siege of Riga and Narva. But Charles, in a series of marvellous operations, raised the siege of Riga, and dispersed or captured the very much greater force before Narva in November 1700. The continued successes of Charles did not check Peter's determination to maintain Augustus of Saxony and Poland against him. It was during the subsequent operations against Charles's lieutenants in Livonia that Catherine--afterwards to become Peter's empress--was taken prisoner. The Tsar continued to press forward his social reforms at Moscow, and his naval and military programmes. His fleet was growing on Lake Ladoga. In its neighbourhood was the important Swedish fortress of Niantz, which he captured in May 1703; after which he resolved to establish the town which became Petersburg, where the Neva flows into the Gulf of Finland; and designed the fortifications of Cronstadt, which were to render it impregnable. The next step was to take Narva, where he had before been foiled. The town fell on August 20, 1704; when Peter, by his personal exertions, checked the violence of his soldiery.