In the first image we can see the possible idiomatic distribution of this area. The language varies gradually as we move through the area. The barrier of the pyrinées produce a more abrupt differentiation.
Notice the second image how the language changes gradually as we go from the South of Valencia to the North of Lleida, some French philologists describe the Catalan language of Lleida as the Valencian language of Catalonia. However, in the Barcelona-Gerona area the difference is more abrupt.
Occitan refugees entered through the Girona Pyrenees, which is the easiest step, and from there they went down to Barcelona, taking with them a differentiated Occitan, which when mixed with the one spoken in the area produced this anomaly.
This emigration from Occitania was repeated in the sixteenth and seventeenth centuries, and also for religious reasons, further accentuating this linguistic anomaly.
The Romance language of the Balearics also received an important influence of the Occitan immigration, fruit of the Cathar persecution and the coming of settlers from the territories that the Kingdom of Majorca owned in the Occitan area. Without forgetting, of course, the strong relationship that the Balearic Islands had with the County of Ampurias for more than 100 years, before the Muslim invasion.
Only by way of clarification, saying that the Catalans repopulated the Balearic Islands and Valencia is as stupid as believing that the Galicians repopulated Portugal.
In the 15th century, the Valencian Golden Age, emerged , with authors such as Ausias March and Juanot Martorell, no doubt the result of the decline left by Valencian-Andalusian poets and writers.
While Catalonia will not have its own golden century until well into the 19th century, with "la Renaixença".
Although the historical trilerism, typical of Catalanism, has appropriated the Valencian Golden Age.

Tirant lo Blanch. Wikipedia
Its author, Joanot Martorell, does not say that he writes in Catalan but in Valencian or Romance.
The Catalan authors of the XV - XIX centuries, do not call Catalan to the language in which they write, but Limousine (translation).
After the War of the Spanish Succession These are not the substitution of Catalan for Spanish, as Catalanism would have us believe, but the replacement of Latin that was still used in the administration of justice by Spanish.
In contrast, in the south of France, after the Revolución Francesa (1789), the Occitan language is relegated to oral use, imposing the French language. This will cause a slow but firm path towards his disappearance.
While the Catalan language from the nineteenth century, begins a great boom propitiated mainly by the wealthy Catalan bourgeoisie.
It is from the second third of the 19th century, when Catalanism began to gain strength, with the support of the powerful Catalan bourgeoisie. This really is the most important factor in the rise of Catalanism, inside and outside of Catalonia.
The possibility of financing literary competitions, academies of the Catalan language or buying accessions, and marginalizing anyone who does not agree with the principles of Catalanism, an attitude that has lasted until today.
A clear example of this is Wilhelm Meyer-Lübke, linguist, romanist and Swiss-born Hispanist, in 1890 he assigned to the Catalan language the status of Provencal dialect in his "Grammar of Romance Languages", where he says:
"In the East the transition is operated little by little with Catalan in Roussillon: This latter speaks (parlen), which is nothing more than a Provencal dialect ...."
Surprisingly, he changed his mind when, in 1925, he was named, "Maintainer of the Jocs Florals of Barcelona" and had been "onerously loyalized" by the Catalan bourgeoisie. It was then that he began to use the name "Catalan language" widely.
Between 1904 and 1932, Pompeu Fabra published several works, which lay the foundations of standard Catalan, based on the Barcelona dialect, and to the detriment of the rest of the dialects spoken in Catalonia and the rest of the territories of the old Crown of Aragon. Both the language of the Balearic Islands and Valencia, should adhere to this regulation.
Philologists of the prestige of Father Batllori are totally opposed to the imposition of the barcelonian dialect as standard Catalan.
Father Batllori, historian and university professor. Prize Prince of Asturias 1995 and doctor honoris cause by different Catalan univesidades. In 1992, University of Gerona:
"The Catalan of Barcelona that is tried to impose in Valencia is an infamous and infamous dialect, what is being tried to impose in Valencia and the Balearic Islands, as a literary language, is the infamous dialect of Barcelona" ..., "it will never be accepted that a dialect as infected as Barcelona can be imposed as a national language "...

It seems that Batllori was wrong, if they have managed to impose that infamous and infamous dialect. The economic power of the Catalan people has passed as a roller on any discrepancy, calling it paletism and ignorance, although philologists of the importance of Batllori were totally against it.
Conclusion:
To this day, Catalanism continues with its bipolar behavior.
While on the one hand, he does not stop using victimhood to claim his differentiating claims towards Spain. On the other hand, it acts with arrogance and contempt towards the rest of the territories of the Crown of Aragon and its languages, trying to blur any differentiating feature, to be integrated into its delirious version of history, as the Catalan countries.
Different political and economic situations mean that Occitan has practically disappeared, while the Catalan dialect has lasted.
For this reason, the support of the acclaimed Catalan bourgeoisie has been fundamental.
Occitan today survives as best he can. There are several publications in this language, that if we compare it with the Catalan and Majorcan, we should ask why the Majorcan is a dialect of the Catalan, while Catalan is a language different from Occitan.
When I say Majorcan I do not mean what is spoken in the Balearic television news, but the one spoken by the people .
Text in Occitan.
"Comunicat de l'IEO (Institut d'Estidis Occitans): contribucion al debat pertocant a las proposicions de lei constitucionalas.
Vaquí lo punt de vista de l'IEO pels debats a venir suls tèxtes de proposicion de lei constitucionalas, per modificar la Constitucion dins la perspectiva de ratificar la Carta Europenca de las lengas regionalas o minoritàrias."
Text in catalan.
"Comunicat de l'IEO (Institut d'Estudis Occitans): contribució al debat pertocant a les proposicions de llei constitucionals.
Vet aquí el punt de vista de l'IEO pels debats a venir sobre textos de proposició de llei constitucionals, per modificar la Constitució dins la perspectiva de ratificar la Carta Europea de les llengües regionals o minoritàries".
Text in Majorcan.
"Comunicat de s'IEO (Institut d'Estudis Occitans): contribució an es debat pertocant a ses proposicions de llei constitucionals.
Vet iquí es punt de vista de s'IEO pes debats a venir sobre texts de proposició de llei constitucionals per modificar sa Constitució dins sa perpectiva de ratificar sa Carta Europea de ses llengos regionals o minoritàries."
Text in English.
"Statement of the IEO (Institute of Occitan Studies): contribution to the debate corresponding to the proposals of constitutional law."
Here is the point of view of the IEO for the debates to come about texts of constitutional law proposal, to modify the Constitution within the perspective of ratifying the European Charter of regional or minority languages. "
