Pirate King Settlement

Overview

Pirate Strongholds, or Tier 3 pirate islands, house tougher pirates than the Pirate Townships, and are more common past 30 N/W/E/S. These islands will generally be more flat and have less trees than normal, along with a big wooden fort located somewhere on the island. Besides that, there are campfires and small huts strewn around the island.

The fort itself contains a few huts, Storage Crates, a throne in the middle and a Gold Storage Chest, which is only openable with a Gold Chest Key.

Pirates that may appear on these islands:

Pirate Elite Brute
Pirate Elite Herbalist
Pirate Elite Navigator
Pirate Elite Captain
Pirate Elite Bounty Hunter (Only after you kill enough Elite Pirates)
Pirate King (Only after killing 3 Bounty Hunters)

Resources available:

The Bounty Hunter

The Pirate Elite Bounty Hunter doesn't appear on the island normally. When you kill enough Pirate Elites (the amount seems to be completely random), text will appear on the screen signifying that the pirates have taken notice to you. After a few more kills you'll get a similar message that the pirates are plotting against you. After ever more kills, you will be informed that there's a bounty on your head. Now the Bounty Hunter spawns near the fort of the island. Only one Bounty Hunter spawns per bounty, and after killing the Bounty Hunter you can proceed to kill more Pirate Elites to get another bounty on your head to make him appear again.

The Pirate King

After killing 3 Bounty Hunters, a message appears saying you can hear trumpets in the distance. Not long after, a Pirate King will appear inside the fort. It will be the Pirate King of the North/West/South/East, depending on what coordinates you are at. When you approach him, battle music will start playing and will only stop once either of you die, or you run far enough away. Killing the Pirate King resets this entire event and you can start over by killing more Pirate Elites until Bounty Hunters show up.

Trivia

Very few resources spawn on these islands compared to other locations.
The first message of the pirates' intent reads: Word begin^(sic) to spread amongst these pirates of your deeds.
The second message of the pirates' intent reads: These pirates begin to plot against you.
The message which makes the Bounty Hunter appear reads: A bounty has been placed upon your head.
The message which appears after you kill a Bounty hunter reads: A bounty hunter has been slain. This news travels far.
The message which appears after you kill two Bounty Hunters reads: A second bounty hunter has been slain. This news travels far.
The message which appears after you kill three Bounty Hunters and makes the Pirate King appear reads: A third bounty hunter has been slain. You hear faint trumpets in the distance.
There is currently no message for killing the Pirate King.
If you kill more Pirate Elites after spawning the Pirate King but before killing him, you can get the messages to appear. Perhaps this could lead to being able to spawn more than one Pirate King at a fort. (untested)