Principi is a Faction in Pillars of Eternity 2: Deadfire.
The Principi are a devout group of sailors descended from refugees who count pirates, smugglers and mercenaries among their numbers.
Responding to the collapse of Grand Vailia (2720 - 2760 AI ), noble families packed up their households and sailed abroad seeking opportunities away from the shadow of their homeland. Over time their old world traditions evolved into a new identity as the Príncipi sen Patrena - the Princes without a Homeland, a loosely-connected and regulated organization of pirates.
They sailed around the Eastern Reach until they reached Deadfire, where instead of settling the islands, they continued their shipboard life. Seizing opportunities where they could, they gradually became pirates, smugglers, mercenaries, and merchants of ill repute. The process was a result of the unraveling of the diminishing empire's trade routes, with the remnants seized aggressively by Rauatai and the Vailian Republics. The exiled families of Vailia found themselves faced with poverty. In response, they resorted to the aforementioned piracy and crime. However, in so doing, they also evolved a shared sense of belonging, a common identity that abandoned the ancient class divisions of Vailian in favor of a single, united people without a homeland: The princes.
The first families initially landed toward the warm, northern portion of the archipelago, but the Príncipi have expanded their reach since then, and their ships can be found anywhere in Deadfire. They tend to lurk near trade routes and settled areas, though their havens are necessarily more remote. While the Príncipi do not found formal cities, they have semi-permanent colonies all around the archipelago where members may safely land for repairs, R&R, or to purchase new supplies. The locations of these havens are typically known only members (or extremely close associates) of the Príncipi. Over time, their ranks have swelled to include Deadfire's indigenous peoples (Huana) as well as enterprising or desperate individuals from other countries and cultures not aligned with the Republics or Rauatai (Dyrwood, Aedyr, Readceras, Ixamitl, etc.)
Principi faction Quests
Your reputation with a faction decides how they see you, there are three types of reputations you can have with a faction: good, bad, and mixed. Losing reputation and gaining reputation don't cancel each other out, but instead are tracked separately. If your positive and negative reputation are around the same, your overall reputation will be mixed.
If your reputation with Principi is bad, all Principi ships at Deadfire archipelago will turn hostile and try to hunt you. Including some special captains. If you are in good relationship with Principi and complete the quest A Dance with Death, you can get a special galleon named The Floating Hangman.