The room is furnished in a Custavian style with furniture as a lounge. Gustavus III was an art-loving king and a skilled politician who returned decision-making power from the nobility to the king. The officers of Suomenlinna Castle supported the king in his coup d'état. Gustav III fought against Russia from 1788 to 1790, and ships from the Suomenlinna archipelago took part in naval battles. He was eventually assassinated during the opera masquerade in 1792.