Throw in some nightingales to feast on the deadAfter further research:
The Principalities of Catalonia experienced a 37% population loss during 1347 to 1497 due to the plague. Barcelona was the capital of Catalonia. Catalonia was under French and Spanish monarchy rule, and did not fully become a part of Spain until after the Franco-Spanish War. Catalonia sided with France during that war.
That would be how individuals left France and became Spaniards. Lancing canes and the lancing of buboes answers the rest.
I probably should forwarn people who are unfamiliar with me when it comes to riddles. I’m very tenacious and have an abundance of useless trivia.
So, plague doctors in Catalan or Barcelona.