Final answer:
The war between Charles and Peter is called the Great Northern War.
Step-by-step explanation:
The war between Charles and Peter is called the Great Northern War. This war was fought from 1700 to 1721 and was primarily a conflict between the Swedish Empire, led by Charles XII, and the Russian Empire, led by Peter the Great. The war had significant consequences for both countries and resulted in territorial changes and shifts in power in Northern Europe.