Kastelholm Castle

A wooden kastell stood on the island before the stone castle, begun in the 1380s on the southern side. Kastelholm first appears in 1388, in a charter of Margaret I of Denmark transferring a large part of the estate of Bo Jonsson Grip, its first recorded occupant, to the queen; since Grip's own will of four years earlier does not name it, the historian Reinhold Hausen dated its founding to between 1384 and Grip's death in 1386.

The island, about 1.7 hectares, was ringed by two or three rows of poles against landings. With Kastelholm in Margaret's hands Åland became an administrative district of its own with the castle as its centre, and in 1418 Åland was made an independent fief and given to the Dane Bengt Pogwisch.

When Pogwisch died his widow Ida Königsmarck kept the fief, to the annoyance of the Swedes, says the Karl Chronicle. During the Engelbrekt rebellion the rebels besieged the castle on behalf of Erik Puke and took it in September 1434; Puke was beheaded in the late winter of 1437.

The Danish naval commander Søren Norby seized Kastelholm early in the 16th century, and Sten Turenpoika was carried off a prisoner to Denmark. Hemming Gadh, who held the castle from 1514 or 1515 for four years, claimed to have “built” it, probably repairing Norby's damage. The Danes took Kastelholm again in September 1520 and Christian II installed Lyder van Offensen, who held Åland until the summer of 1523, when he sailed to Stockholm and surrendered on 18 July; the Swedes occupied the empty castle.

Gustav Vasa, king from 1523, granted Åland to Ivar Fleming, who held it until 1537 as Kastelholm's last fief-holder; thereafter the king took it under his own household and bailiffs governed. The first of them, Olof Trottenpoika, reported in 1543 that the castle was badly damaged, and repairs ordered by Gustav Vasa probably ran into the 1550s. The castle kept a shipyard employing about 50 shipwrights in the 16th century, and its records of 1559 carry the first documented presence of Roma in Finland.

John III, who had stayed at the castle as duke of Finland, held his deposed brother Eric XIV and Eric's wife Karin Månsdotter prisoner there in the autumn of 1571; tradition places Eric's room on the third floor of Kurtornet. He had granted Kastelholm for life to the queen dowager Catherine Stenbock, a political rival of Eric, whose tenure ran to 1621.

In January 1599, with Duke Charles's governor Hans Klasson away in Stockholm, Arvid Stålarm crossed the ice with 18 sledges and 40 men and took Kastelholm for King Sigismund without a fight, installing Salomon Ille as commander. Charles sent Klasson back in April with 400 men; that siege failed completely, as did a second attempt in mid-July. The decisive day was 31 July, the duke's attack led by Admiral Joakim Scheel, who had told Ille the day before that he had brought four heavy guns. By some accounts the castle surrendered without a fight; by others Charles's men took it with artillery and left it heavily damaged. The officers were taken to Turku and beheaded.

Fire damaged the castle in late autumn 1619, and Gustav II Adolf told the Åland governor Stellan Otto von Mörner to put it right; the master builder Hans Esslinger was engaged and the accounts show work running until 1631. The rebuilt castle soon lost its purpose: in 1634 Åland was attached to Turku county, and Kastelholm ceased to be an administrative centre.

In 1642 the highest responsibility for the castle lay with a clerk and a caretaker. It served for a time as a prison — Claes Bielke, condemned in the Linköping bloodbath, was banished here — and the Kastelholm witch trials were held in the 1660s. During the Great Wrath the defences were raised once more with wooden palisades, but no enemy came. A fire in 1745 destroyed much of the structure; the north wing came through best and became a grain store, and the castle was abandoned in the 1770s.

The ruins were first conserved in the 1890s, while the north wing served as a grain store until the 1930s, when it was made Åland's first cultural-historical museum. The provincial government began a restoration programme in 1979, and excavation and restoration ran from 1982 to 1989. Since the 1990s the partly restored castle has been a museum, one of five surviving medieval castles in Finland reckoned architecturally significant with Hämeenlinna, Olavinlinna, Raseborg and Turku; the Jan Karlsgården open-air museum stands beside it.