Barking up the wrong tree? Well that could be the start of another clue: trees and language spoken in a city in Italy many, many years ago but that area would be a distance from this airport although the airport could be used for international access.
A simpler clue would be to say the Britain clue relates to royalty.
MJG
I do have a layout drawing for Holy Saturday, if the challenge goes that long. as there is also a Christianity link to the city which is served by the airport.