Interesting piece of fiction , specially the part about Unicorns
Mostly , back in the So called Vasco Di Gama days , Europe was in ways between French , Spanish and British
Gold was a traceable commodity
Trade was normally done via land / sea routes maintained by Muslims countries.
Muslims had lost Granada 150-160 years ago , 1.5 generation ago
Quest began to gather more gold for the new Empires , French - Spanish - British - Portuguese , so they can influence more. More gold = More influence.
Vasco De Gamma / Columbus were same batch one was Portuguese other was Spanish , they wanted to conquer land for their Kings , and this their Kings had allocated them ships / Men to discover the new lands to expand their Empire.
Columbus (Spanish Expedition) reached , America/South America , and started Ethnic cleaning of local cultures and Traditions , as Gun powder / Cannons had been already discovered in Europe
Mean while Mr Vasco De Gamma reached India via Sea route
However , the path was 50% already discovered by other expeditions of the time
Route between Egypt and Europe was controlled by
Ottoman Empire , as Trade Tax was collected by Muslims
as trade went thru their countries (Mainly thru Egypt /Syria / Persia to India)
People like Barbosa , and Ottoman Navy controlled the sea route which was known
Both Spanish/Portuguese wanted to avoid Direct war with Ottoman Empire
However as we know there was no Suez Canal , in Egypt otherwise Ottoman Navy would Navigate to India
There was no need of new route as far as Ottoman Empire was concerned as they can do cheaper goods move via Land.
Portuguese and Spanish , had a Alliance , their main enemies were French - British - Dutch around 1500-1560
When Philip II of Spain, I of Portugal, inherited the Portuguese crown in 1580, this began a 60-year union between Spain and Portugal that has since been given the historiographic term of the Iberian Union. Though the realms continued to be administered separately, the Council of Portugal ruled the country and its empire from Madrid. As the King of Spain was also King of Portugal, Portuguese colonies became the subject of attacks by three rival European powers hostile to Spain: the Dutch Republic, England, and France. With its smaller population, Portugal was unable to effectively defend its overstretched network of trading posts, and the empire began a long and gradual decline.
Obviously India had GOLD , lots of it in temples and I am sure Mr Vasco De gamma's mouth must have been watering up when he saw all the Gold in Temples in India
Just like Mr Columbus started his Ethnic cleaning operations in South America , Mr De Gamma was also making sure a Military expedition landed in India in short term future