Scholar
Antonio de Nebrija (Castilian): "The Lusitanian standard is captured, which was a valuable insignia, yet by the negligence of Pedro Velasco and Pedro Vaca, to whom it was entrusted, as [already] mentioned, it is subsequently taken up by the enemy"
Context Battle of Toro.
Portuguese were referred as Lusitanians by their Castillian counterparts.
It's not unfeasible to call it Lusitania.
Iberian Union could be a good name aswell, since if Portugal forms Spain, it loses its heraldry in the flag which makes 0 sense.
Is it as big of a meme than the tag germany currently in game?
Why would they call themselves hispania when one of the grandsons of the "Emperor of Hispania" clearly fought to form his own country, and be separated from that political entity?