Hearts of iron: Ironclad Campaigns, 1864 and 1866.
During the age of nationalism, the Austrian Navy fought two campaigns at sea. The first came in 1864, when an Austrian squadron sailed to the North sea to challenge the Danish blockade north German ports. the Austrians fought the Danes at the Battle of Helgoland, winning a strategic victory by breaking the blockade. Meanwhile. Austria's Prussian allies fought an inconclusive engagement with the Danes at Swinemunde.
Two years later, the Austrian fleet fought the Italians in the first open-sea battle between Ironclade fleets, at Lissa in the Adriatic. An Austrian victory, it prevented Italian seizure of the strategic island of Lissa.
Hearts of Iron is loosely based on the Great War at sea series of games.