So what if an equivalent of Dorne of the GOT series or ASOIAF novel existed and persisted in real history on the Iberian Peninsula ? So there are several examples of Moorish and Christian culture merged to some degrees and even transcultural transreligious marriages. So interesting eould be an Iberian state or a dominant one with mixed Spanish and Moorish customs. Maybe even a Christian Spain with Moorish culture. How could that happen and what is the history ?
Dorne in the ASOIAF had the same faith as most of the other seven kingdoms, the faith of the seven. So in this analogy they would still be christian. They had a different culture from the rest of Westeros, though not to different. So I would say a Moorish Christian kingdom or more correctly Amazigh Christian Spain. However lets go further with the analogy then just the surface details since it actually can work.
Founding of Dorne/I
Dorne as a princepality was formed through the alliance of Nymeria who sailed from Rhyone to avoid the Valaryians wrath. She allied herself with Mors Martel and together they defeated the other princes and united the region. Because of her support Mors took the Rhoynish term Prince instead of King.
How can this apply to Real life? First lets have the Visigothic kingdom fracture so that southern Spain is fighting for one another. As Mors location was at the tip of the peninsula, the Mors expy would be based around what is Gibraltar today. There were powerful Amazigh warrior women, such as Kahina in the 700s. So an expy of Nymeria is rather easy, heck it could even be Kahina herself. They could be fleeing Roman attempts to conquer the region(there were conflicts between Amazigh and Romans before) or they could be fleeing the Arabs. Still the Kahina expy goes to southern Spain and allies with the Mors expy and marries him for support. Similar to how the Dornish adopted the term Prince instead of King, the Southern Iberians here take the term Mas or Lord, at least I think Mas means lord from my googling.
Aegon's conquest
Moving on Dornish history the next major event is the arrival of the Targaryen in Aegon's conquest of the Seven Kingdoms. He would however fail to conquer Dorne. During the war with Dorne he would try to lay waste to the cities but in the conquest his Sister-wife Queen Rhaenys.
So how does this apply to our History? Aegon here would be a norman adventure who goes to Spain to set up his own kingdom out of the ashes of the Visigothic Kingdom. He manages to unite all of them but southern Iberia though he lays waste to the realm but the loss of his beloved queen during the war forces him to retreat though the norman kingdom still claims to rule over 'Dorne'
An ambitious Norman knight, Guérôme, takes advantage of the chaos going on in northern Iberia as the northern kingdoms fight each other. Guérôme manages to unite the various realms of Spain under his belt. However when he ventures south past the Sierra Morena mountains he fails to conquer the Dornish even though he devastes their cites. It is with the death of his beloved Queen Rousalie who came with him south that he is forced to retreat North. Despite the fact that for over a century 'Dorne' will not be part of Spain, it doesn't stop Guérôme or his successors from claiming the title 'Mas of Dorne'
Conquest of Dorne
Next major event in Dornish History is the Conquest of Dorne. Daeron I Targaryen who was just a boy of 14 declared his intention of finishing the Conquest. So he prepared for war and marched south through the Red Mountain to Dorne. He would make his way to Sunspear and take the city and bring Dorne into the seven kingdoms. However this did not last long, Lyonel Tyrell was placed in charge of Dorne and murdered by House Qorgyle. This forced Daeron to return Dorne and do more warring. in 160 AC, so when he was 18 years old Daeron made an arrangement with the Dornish to negotiate for Peace but it was a trap and they murdered the young dragon. Thereby securing their independence.
So the young boy Êdouard comes to the throne at the age of fourteen. Ambitious and proud and skilled in military matters he vows to finish the Conquest of Spain and unite the whole region under his belt. He brings up his army and goes to war against 'Dorne' and within a year he conquers Gibraltar. However after placing his trusted duke Remont in charge he returns north. However just a couple of years later Remont is killed by one of the loyal dornish families. Êdouard is forced to return to 'Dorne' and fight but the peace negotiations between the 'Dornish' and the Spanish proves to be a trap and Êdouard is killed. The death of young Êdouard the brave, breaks morale for the Spanish forces and independence for 'Dorne' is secured.
Bringing Dorne into the Seven Kingdoms.
After the death of the Young Dragon things were tense between Dorne and the rest of Westeros. Dearon's successor Baelor was a pious and devoted king to the seven faith and pardoned the Dornish hostages and began to work on mending ties. Baelor would famously walk barefoot from King's landing to Sunspear escorting the hostages. At sunspear the Prince of Dorne and Baelor came to an agreement regarding peace. Bealor would agree to marry his cousin Daeron to Princess Myriah Martell, the eldest child of the Prince of Dorne.
This brought peace but did not bring Dorne into the Seven Kingdoms. That happened later when Dearon took the throne as Daeron the Second. Daeron began negations with the Prince of Sunspear, Maron Martell on incorporating the kingdom into Westeros. As part of the agreement Maron married Daeron's sister Daenerys Targaryen. The negotiations also brought a number of privilages for the Dornish, such as keeping their customs and titles like Prince instead of becoming Lord. This allowed Dornish influence to grow in the court and was a significant factor in the First Blackfyre Rebellion. Dornish aid and support during that conflict finally brought the Dornish into the seven kingdoms.
Also for culture it was during the reign of Maron that the Water gardens in Sunspear were built. Daenerys Targaryen introduced the custom of hosting the children of the Lords of Dorne, later it came to include smallfolk children as well.
This is super easy to see happening in this timeline considering that in OTL this was exactly how Spain got united anyways. Pretty much everything here works just by changing things. But to continue the narrative.
Batistin succeeds Êdouard. Batistin is a pious Christian king who wishes to mend ties between Christian Spain and 'Dorne'. To secure peace he decides to walk barefoot south through southern Iberia to Gibraltar. There the hostages that Êdouard took during the Conquest are returned and to further strengthen peace he marries his cousin, also named Êdouard, to Tiziri. When Êdouard the second comes to the throne he agrees to a marriage pact marrying his sister Délaïde to Bartolomé the current Mas of 'Dorne'. Part of the marriage agreements is to allow for more rights and privileges that other lords in Spain don't have. This however fuels resentment and provide's fuel for Êdouard's bastard brother, Edelmir, to launch his war for the throne. As the 'Dornish' and the spanish fight side by side it helps to ease tensions and after long last 'Dorne' is brought into Spain.
Bartolomé would expand the royal palace in Gibraltar to include a Garden filled with fountains. Délaïde would begin a tradition of hosting the children of the Lords and Ladies of 'Dorne' at these water gardens when they visited.
There is other events in the history and obviously the events of the books, but I think this gives us a good image of what a realistic Dorne might potentially look like. Thoughts?