Here are a couple factoids that may serve as story seeds, and if anyone else has seeds please post. I'm always happy to use & abuse other folks idas.
When I lived in Tunis I met a local professor who's studies were on the history of Medicine in the Arabic/Muslim world. At the time he was working with local historical documents in tunis that dealt with bird hospitals and falconry schools in Tunis. Apparently thru much of history of the city, including the Medieval period, the falcon breeders, trainers, and the teachers of falconry were world famous, and attracted clients from all over Europe. The understanding of care for and healing of birds was focused in Tunis.
Maybe a local friendly lord sends his son to study falconry in Tunis and the covenant is asked to send a magus along to babysit the boy.
My interest in Ars Magica in the early 1990ies led me to start collection Medieval Spainish coins. As I learned more about Medieval numismatics I was suprised to learn how counterfeiting impacted the period. Most lords/Cities minted their own conis, and the value tended to be placed on the weight & metal, rather then where it was minted. However a couple of shady practices did develop. Clipping; shaveing small bits from the edge of a coin to save, and then passing the slightly smaller coin off on someone without a scale. Counterfiting; some areas became well know for their ability to produce pure quality metals, (Thebes & the Levant for example), coins from such areas became a bit more valued and so these coins were copied on occasion.
Maybe a local unscrubulous merchant is cheating locals in such a way and somehow the Covenant gets the blame.