Very interesting and a great coin. In 1675 Christian V was the King and had only been so for a short time. His father had made Denmark an absolute monarchy 10 years earlier which also meant the Norwegians, which were part of Denmark until 1814 when the Swedish seized them.
Denmark lost a lot in this war, including a big part of Skane (Southern Sweden) with Malmo and Helsingborg.
In 1677, the pride of the Swedish fleet - The Vasa sunk and Karl XI saw his glory slightly sapped. It was nothing however for what happened to his successor when the Russians had a powerful new ruler and that new ruler allied with the Danes.
The coins of Sweden of the time are interesting as they look a lot like English coins of Charles II.
Denmark is one of my obsessions, in one year I have accumulated a massive collection of stamps (Although my coins are mediocre) and memorised every king back to Valdemar Attedag (1340 - 1384AD).
Interesting too is the Danish attack on Stockholm in 1520 in which Frederick 1 destroyed it and the Swedish never forgot and then the round churches on Bjornholm which date from 12/13th century rivalries and were half church, half fort and refuge.

This rock in Norway is interesting showing the various rulers since 1623 when Christian IV of Denmark carved an inscription and various rulers through to 1740s added their pieces. Then no one bothered until the 1840s when Swedish kings added their cyphers and finally with the 3 kings of Independent Norway since then. Harald V carved his early on when he became king.
Norwegian kings of course are merely an offshot of the Swedish royal family.
The rock has been lovingly cared for as shown.
Loving Halfcrowns. British and Commonwealth coins 1750 - 1950 and anything Kiwi.
If it's round, shiny and silvery I will love it.