Headcanon

[lionofthenorth]

Suiones / Suehans / Suetidi - Svear

The Roman historian Tacitus mentioned the Suiones in his book Germania, from around year 98. The Swedes (Swedish: svear; Old Norse: svíar; Old English: Sweonas; Latin: Suiones, Suehans or Sueones) were an ancient North Germanic tribe in Scandinavia. As the dominions of their kings grew, their land slowly evolved into the modern Swedish nation. (Wiki.)

In my headcanon, the character of Sweden was born shortly after year 0, and absolutely no later than year 400. Since Germania is all the Germanic tribes, I guess that would make him Sweden's "father". Sweden would have been a tiny little one, sort of like Chibitalia, up until the Viking era.

(And while we're at it, I don't think nations have mothers or fathers as in someone gave birth to them. I think it's more the case like when they found America - suddenly there is a new nation-tan to be claimed as your brother!)

Sweden and Finland

The people living in what would become Sweden has had contact with the people living in what would become Finland since the bronze age (1700-500 BC). (Wiki)

This doesn't really fit into Hetalia, though. I imagine that Sweden and Finland met before the Viking age, however.

Finland's name for Sweden Ruotsi comes from Roden, an old designation of the coastal areas of Svealand that in wartime would mann and equip the ships that sailed out in ledung. ( Wiki)

Sweden's name for Finland (probably) comes from the Germanic word Findr, to find. Basically, Finland is calling Sweden Rower, and Sweden is calling Finland Finder. Can't you just see that happen? Sweden rowing over to Finland only to instantly get lost in the forests. (The Swedes were fishermen, not used to the (probably evil) forest. The Finns were hunters, not likely to get lost in their forest but scared of the water.) So, Sweden is deeply impressed that Finland finds his way through the forests, and Finland just can't wrap his head around Sweden rowing across the ocean. In the end, the Swedish fishermen settled down in the coastal areas of Finland that the Finns themselves didn't care about, since they used the forests for hunting. It only became a problem when they both wanted the same farmland, later on...

Sweden officially became Sweden and "got married" to Finland in the 1200s. There was no Sweden before Finland became a part of it. (wiki )
Back then, Sweden consisted of Svealand, Götaland and Österland (Finland.) Just like England represents the United Kingdom when his brothers aren't around, I imagine that the chara we know as Sweden is also called Svealand when Götaland and (nowadays) Norrland is around.