Complex sentence: The Republic of Jamtland was founded in 1963 (recalling the former 10th-century republicy) as a reaction to the emigration from the county, though the actual event that triggered its foundation was the centralist plan of Swedish officials to merge Jämtland County with Västernorrland County.
Split into simpler sentences: The Republic of Jamtland was founded in 1963 (recalling the former 10th-century republic) in reaction to emigration from the county. The event that triggered its foundation was the centralist plan of Swedish officials to merge Jämtland County with Västernorrland County.