the city more professional and to ensure the state-controlled trade. Stockholm thus lost much of the independence it had had during the Middle Ages and became politically and financially bound to the state. During the reign of his sons (1561–1611), the city council remained escorted by a royal representative and both magistrates and aldermen were appointed by the king. Gustav Vasa invited the clergyman Olaus Petri (1493–1552) to become the city secretary of Stockholm. With the two side by side, the new ideas of the Protestant Reformation could be quickly implemented, and sermons in the church were held in Swedish starting in 1525 and Latin was abolished in 1530. A consequence of this development was a need for separate churches for the numerous German and Finnish-speaking citizens and during the 1530 the still-existent German and Finnish parishes were created. The king was, however, not favourably disposed to older chapels and churches in the city, and he ordered churches and monasteries on the ridges surrounding the city to be demolished, together with the numerous charitable institutions. Because Stockholm had a city wall, it was exempted from the tax paid by other Swedish cities. During the reign of Gustav Vasa the city's fortifications were reinforced and in the Stockholm Archipelago, Vaxholm was created to guard the inlet from the Baltic. While the medieval structure of Stockholm remained mostly unaltered during the 16th century, the city's social and economic importance grew to the extent that no king could permit the city to determine its own faith – the most important export item being bar iron and the most important destination Lübeck. During the reign of Vasa's sons, trade led many Swedes to settle in the city, but the trade and the capital needed to control it was largely in the hands of the king and German merchants from Lübeck and Danzig. Throughout the era, Sweden could hardly claim the level of government and bureaucracy requisite to a capital in the modern sense, but Stockholm was the kingdom's strongest bastion and the king's main residence. As Eric XIV's pretensions were on par with those of Renaissance princes on the continent, he afforded himself the largest court his finances could possibly support, and the royal castle was thus the biggest employer in the city. Around 1560–80, most of the citizens, some 8.000 people, still lived on Stadsholmen. This central island was at this time densely