Kastelholm in the Åland islands, where work probably began in 1384, also had the double purpose of administration and defense. Åland was separated from the castle county of Turku and the Åland islanders were reluctantly subjected to a bailiff who ruled over them ‘at close quarters’. The defense function was more complicated, because it involved the defense of more than just the Åland islands themselves. A statement from 1525 describes Kastelholm as “a key to Sweden”, evidence of the importance attributed to Kastelholm as a last maritime outpost in the defense of Stockholm. Such a view was entirely justified in an era when the main thoroughfares were the navigation routes across the seas and through the archipelagos. Kastelholm lost its importance in the 17th century, but the castle still stands, partly ruined, but also with some intact interiors.
Kastelholm Castle, Finland
The five castles mentioned so far were all built before the advent of firearms. They were thus designed to withstand arrows, spears and siege engines, which were used to fire large rocks. This is evident in their outward appearance. The battlements on top of the castle walls were crucial; they were designed to ensure that no one could enter that way. The situation changed completely when firearms were introduced; the defenses then had to be concentrated in special, projecting towers fitted with gun loopholes. It also had to be possible to ensure that attackers could not breach the walls with their firepower. The first mention of firearms in Finland relates to Viborg castle, in 1429.
Author: Carl Jacob Gardberg, Photo: Jiang Ping, Finnish Tourist Board