“Well those on the outside call it Evercastle,” said King Noffa XVII. “I presume they’d rather not be reminded of the impossibility of conquering our city.”
“Impossibility?” prompted Ne.
“Of course my dear!” pronounced the aged king. “This city has been under siege for its entire history. Armies assail it constantly, as regular as the tides. In my lifetime alone, we’ve turned back sixty-four different armies. And we seem to be in a lull this century. My great grandfather Noffa XIV faced upwards of a hundred during his reign! The scholars suspect a dark age has set in to the north and west. Still, it is only thanks to our would-be invaders that we can live as we do.
“See how between the inner and outer walls the battlefield is so lush with vegetation? This isn’t even its fullest extent; we send men to trim it down occasionally so there isn’t as much cover for the enemy. But the truth is that this land is constantly fertilized by the bodies of the dead. It is the lifecycle of this place: enemies besiege us, we shoot them down from our walls, their bodies feed the land, and the land feeds us. We have no hope for reinforcements or supplies, and no need. A wholly self-sufficient kingdom in a city.
“If ever the invasions ceased, we would have to greatly expand our fishing operations, but worry not my child, that day will never come. We allow enough soldiers to escape and spread word of our wealth and power that there is always a hunger out there.
“A little exaggeration goes a long way. Noffa IX once supplied our archers with emerald-tipped arrows to aim down at the arrayed attackers. Never fired a single one! But rumors still spread that we were both rich beyond belief and running out of conventional armaments. There are riches, of course, but in truth we are only living slightly larger than our neighbors. Most have realized this by now.
“Then what prize do our assailants truly seek? Why, the city itself! Any footsoldier may be fighting for potential plunder, but their leaders know it is our security from war that is the true advantage.
“In some eras, our enemies have used infernal devices to try to batter down our walls. But within our city we have cultivated the greatest engineering minds the world has known, and they can repair anything. So while any individual brick may not last a decade, the walls remain. We sustain the walls, and they us. There is no frontal assault, even by sea, that can defeat us.
“They will never…” King Noffa trailed off. “Which of my grandkids were you again? Not Noffa XIX…?”
“So no one has ever snuck in, assassinated the monarch, and took their throne by subterfuge?” asked Ne.
“Hmm. I suppose that’s how Noffa I came here, beginning the dynasty,” considered the venerable king. “Why do you ask?”
Ne’s dagger took him in the throat. Their fingers barely caught the crown before the royal body tumbled over the inner wall’s parapet.
“Well that’s step two done,” Ne said to the night.
(I was inspired for this setting while watching Rise of Empires: Ottoman, which I highly recommend.)