The Baltic Union, based at the year 1871.
After the bloody Russian Civil War lasting for 14 years, The Kola Merchant Republic and Finland became independent for the first time ever. The movement to separate from Russia had been going on since Russia had taken over that area, and it finally caused the civil war to erupt in 1852. Finland had been a growing concern in St. Petersburg, and it became independent halfway through in 1859. They allied the rebels of Kola, and defeated the Russian forces by pure luck in 1865.
Estonia hadn't been touched by the Russians, and decided to become a part of the Baltic Union. They became a part of the Baltic Union in 1855.
Riga, which had been a growing power in the Baltic area, became Latvia in 1826, and had been nearly defeated by Russian forces in 1838, but they pulled through, and became part of the Baltic Union in 1844.
Since Norway had become free from vassalage by Denmark, they still retained strong ties. They became part of the Baltic Union in 1866, and they currently have a dispute with Finland, which is the light blue area.
Sweden had had several wars with Finland in the past, but currently has peace, and is vowing for leadership of the Baltic Union, which they joined in 1855.
Denmark was the founder of the Baltic Union in 1843, and is the current leader of it to now.