The Battle of Bornholm of 30 May 1563 was the first fighting of the Nordic Seven Years War (1563-70) between Denmark and Sweden. Earlier in the year, as tensions rose between the two countries, Frederik II of Denmark had ordered a naval blockade of Sweden and dispatched a fleet of eight warships under Jacob Brockenhuus into the Baltic. At the same time Erik XIV of Sweden sent a fleet of twelve ships under Jakob Bagge from Stockholm to Rostock to fetch his potential new wife, Princess Kristina of Hesse.
The two fleets met off the island of Bornholm, at the western entrance to the Baltic. The Danish fleet was at anchor off the island when the Swedes approached from the north. Open warfare had not yet broken out, and so Brockenhuus attempted to stop the Swedish fleet to investigate their intentions. He led three of his ships towards the Swedish fleet, and fired three warning shots. Unfortunately one of those warning shots hit the rigging of the Swedish flagship.
Unsurprisingly the Swedes attacked the three Danish ships. They were soon surrounded, and after four hours of fighting forced to surrender. For some reason the remaining five Danish ships do not seem to have intervened in the fighting although some Swedish accounts of the battle report damage to two more ships. The survivors of the Danish fleet returned to Copenhagen. Bagge reached Warnemünde on 3 June to await Princess Kristina, but the marriage plans soon collapsed, and on 24 June the fleet completed the return journey to Stockholm.