'''Svealand''' was the original core of the ''Svealand'' kingdom in the middle ages until it's consolidation in the 11th century. In the 16th century, the soon-to-be king ''Gustav Vasa'' took refuge in the province Dalarna to avoid the Danish who had massacred the entire Swedish noble on a square in Stockholm, except for Gustav Vasa. Here he got support from the farmers and caused an uprising. He contracted German mercenaries and crushed all Danish garrisons, and finally invaded Stockholm.
As for the rest of Sweden, most people below the age of 40 speak fluent English. Older people will probably understand you but will be less good in expressing themselves. Some people, especially youths, might be able to communicate through German, French or Spanish, depending on what classes they took in school. English is what most people prefer though.