Conversation so far:
who took part in the battle of waterloo
The Battle of Waterloo involved France versus the United Kingdom and its allies.
who were the allies of the uk in the battle of waterloo
The United Kingedom's allies in the Battle of Waterloo were the Netherlands, Hanover, Nassau, and Brunswick.
when was the battle of waterloo
The Battle of Waterloo was fought on Sunday, 18 June 1815.

Question: where was the battle
Self-contained rewrite: where was the battle of waterloo