Sounds way better when you say “I had a meeting with the king of The Netherlands recently” compares to "I had a meeting with the High Commissioner of The Netherlands recently "
It’s the country’s law, you can call the high commissioner “king” if you agree to. Ireland calls its prime minister and deputy PM “taoiseach” and “tánaiste” respectively, which are monarchic titles from the Gaelic clan system
Think of them as prestigious diplomats.
Sounds way better when you say “I had a meeting with the king of The Netherlands recently” compares to "I had a meeting with the High Commissioner of The Netherlands recently "
You can still say “king” if you want
No because a king is different to a high commissioner.
It’s the country’s law, you can call the high commissioner “king” if you agree to. Ireland calls its prime minister and deputy PM “taoiseach” and “tánaiste” respectively, which are monarchic titles from the Gaelic clan system