Charles's Gothenburg was almost wholly inhabited by Dutch merchants and immigrants, and Dutch was the official language within the town. The settlers were attracted to Sweden with the promise of free trade and freedom of religion. They enjoyed privileges such as 20 years of tax exemption and lowered customs rates. In return, Sweden and the west coast could benefit of the skills and trade connections of the Dutch. However, Gothenburg proved to be just as vulnerable to Danish-Norwegian attacks as its predecessors at Nya Lödöse and Älvsborg Town, indeed arguably even more so, as part of Hisingen () was in fact Norwegian territory at this time. Soon after the outbreak of the Kalmar War, on 12 June 1611, the town was attacked and burnt by a Danish-Norwegian force. Foundation of Gothenburg In 1621, King Gustav II Adolf, the son and successor of Charles IX, decided to make yet another attempt at founding a city on the Göta Älv. According to legend, the king was searching for a suitable location when suddenly a dove fleeing from an eagle landed at his feet, seeking shelter. Gustav took this as a sign from God and declared, Här skall staden ligga! ('Here shall the city lie!'). In order to ensure the new settlement did not suffer the same fate as its predecessors, it was provided with a substantial network of fortifications, later augmented by the twin fortresses of Skansen Kronan and Skansen Lejonet. As at Charles IX's Gothenburg, the majority of the initial inhabitants of Gustav Adolf's Gothenburg were immigrants, and above all from the Dutch Republic. Indeed, the initial city council comprised ten Dutchmen, seven Swedes and one Scot. Dutch builders were contracted to plan the new city and construct its fortifications, in part because of their expertise in building on marshland. In order to drain the swampy ground and provide access for shipping, Gothenburg was given a network of canals, akin to those of Dutch cities like Amsterdam, and indeed it appears the plans for the canal network were modelled on those used for the recent Dutch colonial settlement of Batavia (modern Jakarta, Indonesia). The Dutch influence over Gothenburg in its early decades was so strong that it was sometimes regarded as a Dutch colony on Swedish soil; for example one contemporary writer described it as, Gotheburg ab Hollandis aliisque Belgis incolitur ('Gothenburg, inhabited by Hollanders and other Belgians') Over time, however,