Quick Summary
The King's Castle event happens every 2 weeks in Kingshot. (Sometimes the first two Castle Battles can be off schedule.).
The battle lasts for 6 hours. To win, an alliance needs to either hold the Castle for 3 hours straight or have the longest total hold time within the 6 hours.
Winning is a big deal because your alliance can appoint the King of the entire Kingdom, which comes with great perks and rewards. Even if you don't win, participating gives you a good amount of charm materials for upgrades.
