How long have people been referring to the combined kingdoms of Castile and Aragon, etc. as Spain/España (or a derivative). I understand the Romans called the peninsula Hispania, that's not really what I mean, I'm not looking for an etymology. When did people stop referring to Aragon and Castile separately (or together as the combined kingdoms of Aragon and Castile) and start just saying Spain?
I was taught at school (I'm from spain) that during the war against the moors Fernando II king of Aragón and Isabel I Queen of Castilla said: "We are not doing this for Castilla and Aragón, we are doing this for Spain."
They were married and ruled together as if it was one single kingdom.
This happened during the XVth century.
I know that here in /r/askhistorians you like sources, so I'm looking for it now and I will edit the comment later.
Edit: I found some sources:
A book published on 1783 called: "Collection of chronicles and memories of the Kings of Castille", citing Pedro Mártir de Anglería, a chronologist who was born in Italy and lived in the castillian court during the Xvth century, who says: "We call Fernando and Isabel Kings of Spain, because they own the body/land of Spain [...]". https://archive.org/details/colecciondelasc01unkngoog
I also found about Diego de Valera, a diplomatic and writer cleric from the XVth century who wrote "Doctrinal de príncipes" on 1476 where he said to Fernando II: "You will be the king of all the spains". I've found an analysis of an spanish university about that document here: http://parnaseo.uv.es/Memorabilia/Memorabilia13/PDFs/Doctrinal.pdf
I'm sorry, the document is written in spanish.
Although, Hernando del Pulgar an historian from the XVth century relates that on 1479 the royal council determined not to use the title of "Kings of Spain" because of legal problems. Officially the kingdoms were not called Spain yet, so the king and the queen were called by all their titles:
Don Fernando and doña Isabel, by the grace of god King and Queen of Castilla, León, Aragón, Sicília, Granada, Toledo, Valencia, Galícia, Mallorca, Sevilla, Cerdeña, Córdova, Córcega, Múrcia, Jaén, de los Algarbes de Algeciras, Gibraltar and the Canary Islands Count and Countess of Barcelona, el Rosellón and Cerdaña. Lords of Vizcaya and molina
Duxes of Atenas and Neopatria Marquesses of Oristán and de Goçiano.
Probably because of that huge amount of titles, outside of Spain they were already called King and Queen of Spain.
Besides that, the pope Innocent VIII, who designed them as "The Catholic kings" because they defended the christian faith, addressed them as "Kings of Spain" as it is written on this popes grave, in latin: "REGI HISPANIARUM CATHOLICI NOMINE IMPOSITO". Later, the pope Alexander VI on May 4th, 1493 wrote the papal bull "Inter caetera" addressing them as "Kings of Spain" too.