Gustav III of Sweden (1746–1792)

Gustav III was crowned in 1771, after the death of his father Adolf Frederick of Sweden. The year following his rise to power, Gustav III executed a coup to end the power of the corporative system, in which the fortress had a central role. The coup started according to the plan with the siege of Sveaborg.

The king wanted to restore areas lost to Russia in earlier wars by means of an offensive and, at the same time, restore Sweden as a superpower. The Russo-Swedish War, known as Gustav III's War in Finland, was initiated in 1788 when Sweden attacked Russia. Gustav did not achieve his goals, but on the other hand, Sweden was able to keep its borders, though the situation looked occasionally a little worrying for Sweden. During the war, Sveaborg acted illustriously as the naval base of the fleet and, on its part, enabled the crucial victory at the naval battle of Svensksund in 1790.

In 1751, the southernmost fortress of Sveaborg was named after crown prince Gustav as Kustaanmiekka, which roughly translates as ‘Gustav’s sword’. Later on, the name was adapted for the entire island. Gustav visited the fortress many times and personally drafted the sketches for the tomb of his friend and designer of the fortress, Augustin Ehrensvärd.

Gustav III was very much interested in art and science. As a ruler, he observed the ideals of enlightened absolutism.

Gustav III was assassinated in 1792. Gustav IV Adolf of Sweden became king after him.