# Gustavus Adolphus' reconquest of Öland

Gustavus Adolphus' reconquest of Öland occurred from 26 or 27 September to 8 October 1611 during the Kalmar War.

## Background

While Christian IV prepared to return to Copenhagen with the main Danish fleet, Gustavus Adolphus, along with Per Hammarskiöld, prepared to reconquer Öland from Denmark, Per Hammarskiöld also knew the island well. For the invasion, Adolphus gathered three banners of cavalry and some seven or eight companies of infantry.
The cavalry consisted of Hammarskiöld's old unit, the Småland banner, which was commanded by Per Nilsson, and Victori Sim's cavalry company. The infantry consisted of the Drabant Company under Anders Larsson, Gertrom Yggesson's Småland company, Nils Assersson Mannerskiöld's Östergötland company, and most likely Olf Olsson's Västmanland company. The infantry also included men that had recently came from Finland, including Erik Olsson and Bryngen Torstensson's companies, both conscripted in Finland, and a Scottish company under Robert Sim. Contemporary source put the total strength of the force to 2,000 men.

### Prelude

Gustavus Adolphus and his men planned to cross the Kalmar Strait towards Öland with the so-called "little fleet" under Captain Erik Kyle, which planned to set out froim Skäggenäs, a peninsula around 15 kilometers north of Kalmar. Before crossing, Adolphus made contact with local peasants, who promised assistance.
On 25 September, Gert von Rantzau learned of the planned operation, allegedly from observing the Swedish ships in Skäggenäs, and thus led three companies of infantry from his own regiment, under Valentin Rosworm, Christopher Luppert, and Jørgen Baroldt respectively across the strait to Öland. As a result, Öland was now defended by two Danish cavalry companies, being the enlisted harquebusier companies under Jørgen Grubbe and Tessen von Parsow, who had handed over command to Franz Ernst von Dalwig, along with five companies of infantry, consisting of the three companies from Rantzau and two under respectively Mathias Kochheim and Søren Bugge.

## Invasion

It is likely that Rantzau notified Christian IV of the impending invasion, however, the next day, the Danish main fleet returned to Copenhagen with Christian onboard. Later on the same day, in the evening of 26 or 27 September, Gustavus Adolphus crossed the Kalmar Strait, landing near Stora Rör, 18 kilometers south from Borgholm. The operation was flawless, and local peasants met him on the shore with horses for transport, and many peasants joined the force. At Räpplinge, he surprised and dispersed two Danish companies on the way to Borgholm, leaving some 800 Danes killed. The rest escaped to Borgholm castle. When Rantzau attempted to return to the mainland by sea in order to bring reinforcements, his yacht was swept eastwards to Gotland because of unfavourable winds, delaying the response.
Gustavus Adolphus and his forces quickly and easily mopped the remaining Danes up on the island, and on 7 October, Borgholm castle surrendered, and Adolphus marched in on 8 October, installing Per Hammarskiöld as the commander. Most of the German soldiers in the Danish companies enlisted in the Swedish army, while Adolphus sent the others to Kalmar, after they had swore to not fight Sweden for three months.

## Aftermath

Hammarskiöld received the three Swedish cavalry banners and four infantry companies to defend the island, and the peasant representatives who crossed the strait in order to swear fealty to Christian IV were put on trial and later executed for treason. The invasion was Gustavus Adolphus' second independent command, and it is likely that he received advice from the more experienced Hammarskiöld during the operation.
Later, Adolphus returned to his father, Charles IX, at Ryssby. During December and January, Danish forces from Kalmar raided Öland on multiple occasions. However, they did not attempt to reconquer the island.