There can be only one... At least per country. I have the ultimate say until My death or abdication. Since are gentle and kind Others ruthless.

Donald Duck’s nephew did not beat Truman but he was good with decimals

Removing my last, I'm four rooms in sync. Dropping off two, I listen, don't think. Right in between, I do the last line. And without the first, I'm where you reside. I predate the kitchen, with humans I've grown. And though I am ancient, still found in the home.

A dive into a swimming pool you will not see at the Olympics, or something Bob Dylan and Peter, Paul, and Mary asked how many times they would fly before they’re forever banned.

I circle a castle but I'm not a wall, I hold back the enemy, yet let no stone fall. Fill me with water and I'll keep you afloat. What am I?