Portuguese Traders
From Warpedia
The Portuguese Traders are a fleet of Christian (Catholic) traders from the country of Portugal in Shogun: Total War that will visit Japan periodically during the base game's campaign. They are one of two "factions", the other being the Dutch Traders, that will visit Japan numerous times during the campaign to negotiate and trade with numerous factions, offering advantages in exchange for favors. Usually beginning to appear from turn 15 onwards, the Portuguese Traders are represented by a Portuguese carrack that will be docked with the port of the faction it is trading with, changing this location various times over the campaign. Upon arriving, they will request a presence with the player's daimyo in the throne room much like another faction's emissary would. They will always be the first to open trade with the Japanese, with the Dutch Traders coming much later.
The Portuguese Traders will offer to trade gunpowder weapons in exchange for a trade agreement and the faction's conversion to Christianity, which will give the faction access to gunpowder units, the priest agent type and access to build the Portuguese Trading Post. Converting to Christianity creates immediate public order issues for the faction converting to it: their Dutch counterparts offer no such caveat, offering gunpowder units free of any conversion requirement, although coming later than the Portuguese. If the faction rejects their offer, the Portuguese will return later to offer it again, and in the mean time will go to other factions to offer the same terms. Once the Dutch Traders arrive, Portuguese Traders will appear less frequently, and eventually will be replaced by the Dutch Traders entirely late in the campaign.
Despite technically being their own faction, the Portuguese Traders hold no territory, cannot be engaged in diplomacy (outside of their visits and offers of trade), possess no forces, will not declare war and cannot be declared war upon, and overall do not behave like a conventional faction would. Their sole purpose in the campaign is to provide access to gunpowder units, the priest unit, the Portuguese Trading Post building and in regards to the Christianity mechanic. The carrack representing them on the campaign map cannot be interacted with, as it is just a texture that will change position on the map. They do not appear in the Mongol Invasion expansion.