Barbuda - Fernando I Porto mint

The barbuda takes its name from the visored helmet depicted on the coin — though you already know what's on it. What the image doesn't explain is why Fernando I needed to mint so aggressively: his three wars against Castile between 1369 and 1382 drained the treasury so thoroughly that the Crown debased its billon coinage repeatedly across the reign. The Porto mint operated alongside Lisbon precisely to meet this pressure, and surviving examples from Porto are meaningfully scarcer than their Lisbon counterparts.