In 1512, a ship’s pilot in service to the King of Portugal penned a real-life treasure map. The story of the map’s production is a bizarre one, and the map itself makes excellent inspiration for your own adventures.
In the Middle Ages, the spices nutmeg, clove, and mace were grown only on a handful of islands – the Malakus or Spice Islands – in modern Indonesia. Europeans could only buy them from Venetian middlemen, who had an exclusive trade with the Arab merchants who carried the spices west. At the start of the 16th century, Portugal was dead set on finding the Spice Islands and establishing their own trading relationship. They would cut out the Venetian and Arab middlemen and make a fortune!
There was also an urgent need for Portugal to beat Spain to the Spice Islands. At the time, Spain and Portugal were the only two European powers trying to trade with the world outside Europe and the Mediterranean. To keep the peace between the two countries, the 1494 Treaty of Tordesillas divided the world into two spheres of influence. All land east of a meridian 370 leagues west of Portugal's Cape Verde islands fell under Portugese influence. All land west of the Tordesillas meridian (including the lands Columbus claimed for Spain) fell under Spanish influence.
It escaped no one’s notice that the Tordesillas meridian would necessarily continue around the world, dividing the globe in half. Indeed, this would be ratified in the 1529 Treaty of Zaragoza. But no European had ever visited the other side of the world, and it would be centuries before anyone was good enough at determining longitude to figure out where the Tordesillas counter-meridian lay. Effectively, this meant that control of the spice trade would go to whichever power first located the Spice Islands and established a garrison to keep the other out.
This is where our man Francisco Rodríguez enters the picture. He was a pilot working for Portugal. A ship’s pilot is a highly experienced navigator and shiphandler who guides ships through dangerous waters. Rodríguez was assigned to a 1511 Portugese expedition out of Malacca in search of the Spice Islands. (The Sultanate of Malacca, in modern Malaysia, had just been conquered by the Portugese). Rodríguez’s job was to guide the expedition’s ships as safely as possible through unknown waters using local guides for help, and to map the expedition’s discoveries.
The expedition located the Spice Islands. Here we take a brief detour to follow the captain of one of the expedition's ships, one Francisco Serrão. He loaded up a ship with spices in Banda (part of the Spice Islands), but was shipwrecked and either captured or rescued by indigenous pirates. They brought him to the Sultan of Ternate, another of the Spice Islands. There, Serrão married a Ternatean woman and was appointed by the sultan to command the army in wars against the neighboring island of Tidore. Serrão established a fort, but failed to guarantee a monopoly on trade. Oddly, Serrão refused to return to Portugese territory and died ten years later, apparently poisoned by the Tidoreans.
Serrão's fort on Ternate
Meanwhile, our man Rodríguez had returned to Malacca with his maps of the Spice Islands and the seas between them and Malacca. He also produced dozens of panoramic drawings of the islands between Malacca and the Spice Islands. The drawings could serve as double-checks. If you think you’re located here and are looking at this island, you can look at the picture of the island in the book. If the two look nothing alike, you’re probably lost, and it’s better to know you’re lost than to confidently crash into a reef you thought was two hundred miles away.
Rodríguez’s maps were accurate (for their time) descriptions of the very edge of the known world. If you were to let your PCs discover such maps, they could follow them to the fantastical realms of adventure at the fringes of known space, and the source of fabulous wealth that lies there. In this instance, treasure maps do exist! Rodríguez’s maps also contain no speculations. They show exactly what he saw, not what he heard about from his local guides. That means there’s vast stretches of undiscovered country on the edges of the map waiting to be explored.
There’s also the race for the Spice Islands. If you want to actively shove your PCs towards the edge of the map, they could be hired to find the city of gold, lost tribute hulk, or divine sanctum rumored to lie somewhere in that direction. But there’s another group of adventurers hired by a rival faction trying stake their claim first. It’s a race!
The map itself can be a cool MacGuffin too. Even if your PCs have no intention of leaving the well-traveled confines of the known world, a folio of maps like Rodriguez’s could make cool treasure. There might be multiple courts and companies interested in buying them. Some might not want to participate in a bidding war, and instead send henchmen to rob and murder the PCs.
Finally, though the above is a sea story, don’t feel limited to ocean explorations. Adventures based on Rodríguez’s maps can occur just as well on land. Instead of showing the coastlines of unfamiliar islands, the maps might show the meanderings of rivers and mountain ranges never glimpsed by your PCs’ civilization.