A very partial way to present things. This is how it really happened: the Muslim kingdom of Murcia became a Castilian protectorate in 1243 before being annexed by Castile in 1264. Then there was a revolt in 1265-1266 that was put down by James I, the king of Aragon then a Castilian ally, which is what your text is referring to and, as it happens, the area was handed back immediately (I have never heard about another treaty of Cazorla than the one of 1179 so I am quite confused as to when your text is assuming that the area was given back to Castile).
Then only briefly was Murcia occupied by Aragon between 1296 and 1304 during an inter-christian war. So that makes us nearly two-hundred years of Castilian influence in the area: 1243-1296 then 1304-1419, even if some Catalans settled there in 1266, I think this is hardly an argument to change the culture.
as per link below, which says immigration from catalonia and later on immigration from kingdom of Aragon, there is no mention of any castilians in the murcia except border patrols stopping raids from Granada.
http://books.google.com.au/books?id...book_result&ct=result&resnum=1#PRA1-PA1340,M1
The 5 treaties which involved castile and aragon kept changing the border ( the one I mentioned was treaty #2.), but it was castilian land by treaty. the fact are, do not only look at what i suggest , but look at why its wrong. If its not catalonian ( and definetly its not castilian, then its moorish.
Unless things have changed greatly since late 2006, you should have your Basque province in Castile:
If this map is correct, then 387 is basque in culture and language and 388 is basque in culture but is cantabrian in language, ( closer to castilian than basque), so then 387 and 388 will be basque.
This is the same issue we have in the current map..............whats your point ??