Reading Fire & Blood you can see that Dorne not being conquered by the Targs doesn't make sense with all the new information. The guerrilla warfare on a medieval setting doesn't work. You need a great force to ambush armies of thousands of men. And that is negated when the Targs have their dragons to scout. But conveniently Aegon doesn't seem to use his dragons like that. And tge way it ends the First Dornish War with that letter and Aegon all sudden let there be peace... It seems George needed an excuse because he wrote himself again in a corner.
(2) You can say that Aenys and Maegor had other concerns than Dorne. But that Jaehaerys and all his dragón riders didn't try is another war seems rather forced. Specially when the Prince of Dorne makes a casus belli trying to invade the Stormlands with a fleet and the text says Jaehaerys had spies in Dorne. An unlike Aegon this guy knows to use his lizards as scouts as seem with the Vulture king. He wrote in the beginning that Dorne was unconquered. But when he later starts adding new material this clashes with his foundations. I still remember Doran saying that Dorne was the least populated kingdom. I was "you're kidding! Least than the Iron Islands?" Let's not talk about Dorne's armies abilities to enter the Reach and Stormlands unnoticed.
Hi there!
I agree that there are some inconsistencies, but I wouldn't say that this is not entirely believable.
I think you have a rather clear historical parallel in the history of England and Wales. England as the larger and richer kingdom always had the ability to conquer Wales (just like the Iron Throne with dragons always had the tactical advantage over the Dornish). Another historical parallel are the Franks and the Saxons. The possibility was always there but the question always was: Is it worth the effort?
The Saxons and the Welsh were peoples who practiced guerilla warfare and the stronger military nation always can subdue them - as long as they are willing to fight a long bloody war and invest an absurd amount of money to build castles or strongholds etc.
The English kings were busy on the continent and/or with internal strife, and John was the first who made a real effort to conquer Wales (because he needed success) and Wales only very narrowly escaped because of the Barons' wars that led to Magna Charta. Later in the 13th century Edward I took money in his hands and sry, not sry, as much as I feel for the Welsh (having spent a year of my life there), they never stood a chance.
Two campaigns and about 200 new castles later, the Welsh were conquered.
Sort of the same happened with the Saxons. The Saxons always had been a bit of a nuisance to the Franks but the moment Charlemagne decided that he would end this once and for all he managed - even though it took him 30 years - and he never made a profit from it.
So, I'm not saying that the people with better military and more money is always successful but the odds are definitely in their favour. But they have to mean it, so to say. The English kings from William the Conqueror to John never meant it: William the Conqueror made a halfhearted attempt to conquer Wales but gave up when he realized that they were not worth the immense trouble that would be necessary to conquer them. And when Edward I finally succeeded the Welsh Conquest was a hole that ate up a vast amount of English tax money (and people grumbled if it was worth it).
So, if you take this parallel it sort of makes sense that Aegon the Conqueror tried and gave up when his campaign was not immediately successful. Like William the Conqueror he had a reputation to lose. Better back down than get a stain on his rep as an invincible warrior.
Likewise with Jaeherys. He probably could have conquered Dorne but he had other problems as well and he probably decided that it was not worth the effort.
The Young Dragon tried a sweeping campaign for his glory and failed.
In that regard Daeron II was smart when he unified Dorne with the rest of Westeros via marriage - he was not smart in other regards, but that was a politic that would save him vast resources. And at that time the Targs didn't have dragons any longer.
So, I agree that GRRM could have elaborated further (explain why the riches of Dorne are useless for the other kingdoms for example), but I don't think that the situation as such - a more powerful kingdom with a military advantage on the one hand and a smaller realm that remains independent for a long time even for centuries is entirely unbelievable.
It's not a 100% parallel of course, because Wales is also represented in the Vale and the Mountain clans, but I think the general rule that a difficult conquest - even if you have an advantage - is something that simply might not be worth it. I hope I makes sense.
Thanks for the ask!