I'll let all you who don't speak Latin in on the joke in the campaign map:

It means, "Home Sweet Home" :)

If anyone's interested, some of the other cities' modern names are:

Mediolanum = Milan
Patavium = Pavia
Aretium = Arezzo
Moguntiacum = Mainz
Eburacum = York
Lugdunum = Lyons
Ariminium = Rimini

You can probably figure out Londinium for yourself