Yes. From 1396 to 1523, Sweden and Denmark was in a personal union, and still fought several wars against each other.

1434-1436: A revolt led by Engelbrekt Engelbrektsson leads to the first estates parliament in Sweden to declare King Erik of Denmark, Norway and Sweden deposed as King of Sweden. King Erik would then return twice to be deposed again and finally retreat to the island of Gotland to conduct a campaign of piracy on the Baltic Sea.

1448-1450: As King Kristoffer dies suddenlly, the estates parliament elect the Swedish prominent nobleman Karl Knutsson (Bonde) King of Sweden. Both he and King Kristian I of Denmark are elected King of Norway by their respective supporters and war breaks out over Norway.

1452-1457: War between King Karl Knutsson (Bonde) and King Kristian of Denmark.

1463-1471: Since King Karl Knutsson (Bonde) had returned as King, new fighting broke out as King Kristian tried to enforce his claims to the Swedish throne.

1501-1520: Sten Gustavsson (Sture), having been deposed by Swedish supporters of the Kalmar Union 1497 returns and revolts against King Hans of Denmark. This is what leads to Stockholm’s bloodbath.

1521-1523: Gustav Eriksson (Vasa) leads a rising against King Kristian II and finally ends the Kalmar Union.