The Ferrer Family Commercial Enterprise Part of the Foreign Merchants' Trading District of Fort Arltrees The largest building of the Foreign Merchants' District belonged to the Ferrers, a rich Mardierian family of bankers and traders. The palace was an elegant and classy building, for the Mardierian canons, even if a little too modest... for the Essians of the adjacent building, instead, it represented an awful baroque monstrosity!  The Ferrers earned their impressive fortune a the very beginning of the Age of Exploration, when the ports of Terraversa were still closed and most of the Madrician Fleets were still locked behind the Line. At the time, the Ferrer Bank had the great intuition to finance the colonial adventures of the Mardierian Crown: soon, gold, silver, and spices started to flow back to King's Port and Londa, making the financiers rich beyond any measure. In a short time, the Ferrers were also able to launch their own private expeditions: in some periods, their galleons and conquistadores were almost as many as the ones of the king himself. Many years had passed, and now the quartered banner of the Ferrer only represented one of the many flags flown in the New World, and no longer the most feared. The Civil War, followed by the Terraversan Revolution and the Eslando-Mardierian War, represented devastating blows to the power of the Old Empire and its trading companies. Don Francisco Ferrer, one of the current representatives of the Company, had recently arrived at an agreement with the governor of Fort Arltrees: the Ferrers were authorized to establish a trading mission in the settlement; in return, they would act as middlemen in some trading businesses at the very border of legality... One of the most profitable -and possibly the most controversial- of these activities is trying to establish trading bonds with some Lotii merchants, in order to erode their support to the war against Oleon. Technically speaking, war was never declared between Oleon and the Lotii vassals, even if the latter had provided the Imperial Army with ships and numerous mercenaries. Therefore, again in principle, nothing forbade merchants from Banersbi or Bouton to moor in Fort Arltrees, trade with a Mardierian merchant, and leave unharmed... and nobody ever went too deep in investigating their precise nationality! 
For safety reasons, the Southerners were always escorted by Oleonese soldiers, were not allowed close to military installations, and could not spend the night in the settlement; apart from these minor aspects, everything had proceeded smoothly until that moment. The most well-paying trade of the Ferrers in Fort Arltrees is an unusual one, basically creating money out of thin air. Both in the Madrician states and in the Southern Kingdoms, gold and silver are valuable metals, and the former is worth more than the latter.
How much more, however, is a different matter...  A merchant of Oleon, Garvey, or Mardier, for instance, would be happy to pay a golden ingot with nine or ten silver ingots of the same weigth... ...while silver is much more priced in the Southern Kingdoms, and a Lotii merchant would gladly make the same exchange accepting five or six silver ingots. Therefore, by setting the exchange at an intermediate value, both sides would leave richer and happier, buy more metal in their home countries (gold for the Lotii, silver for the Marderians), and repeat the cycle indefinitely! As Fort Arltrees is probably the only place where this type of trade can currently happen, the pressure of the richest merchants on the Lotii commanders could defend the settlement better than a battery of howitzers... at least unless someone decides that raiding and plundering could be a more effective way to get cheap silver! ------------------------------------------------------------------------------------------------ On the upper floor, Don Francisco Ferrer was discussing some future plans with the governor of Fort Arltrees and the commander of his guards. Apparently, there are many ways in which the funds of the Ferrer Company could be put to good use in Fort Arltrees, far from the greedy tax collectors and the cumbersome bureaucracy of Mardier. From his side, Marcel Dubois knew that he had to be extremely careful in all his moves: politics might be far more dangerous than a battlefield, and a forged accusation of corruption or even treason could move him into a dark dungeon or in front of a firing squad really, really quickly.    Additional picture in the spoiler: ------------------------------------------------------------ I hope you enjoy this second build! The backstory is somewhere between the established lore for Mardier, and something I completely invented (the Ferrer Family is something I introduced to build shady and slightly debatable stuff, without my main characters getting directly involved). I hope I didn't go too far in the business with the "definitely-not-Lotii" merchants, which is quite in line with how business and war were managed during the Age of Sails! The differences in the exchange rates between gold and silver in different places, historically, were a real thing: the Portuguese merchants of Macau and Nagasaki earned fortunes in this way, as China was a hungry importers of silver, and didn't use gold for its coins (therefore, the metal was less valuable).