I'm doing further investigation into this, to perhaps shed more onto this mystery. What many of you possibly don't already realize is that going back to the middle ages, Portugal didn't start off as its own nation, rather as a kingdom....same as with Castile and Aragon. Up until around 1680 when it finally gained its independence, the entire Iberian Peninsula was known as "Spain". Back then though, "Spain" as a nation didn't yet exist and was coined more along the lines of "Scandinavia" and "The Balkans".. Though early literature has shown that the Portuguese had referred to themselves as "Spaniards" just as Canadians today refer to themselves as North Americans. I'm making a half-educated guess here... it appears that the LGDs of Portugal have their origin in the northwestern part of the peninsula, maybe north of the Douro/Duero river, which is where "Portugal" started. The Moorish invasion never reached this area. As the Christian (Roman Catholic) Kingdom of Portugal expanded southwards, LGDs that were associated with the Islamic Moorish conquest were culled to the point being virtually exterminated in what is now Portugal (again this is an educated guess/theory of mine). But on the Spanish side the extensive trashumancia movement (started around 1300s, after the Moors were driven out) from the south to the northern parts of the country, allowed for more crossbreeding opportunities. The Trashumancia in Portugal has been miniscule compared to that of Spain, BTW. That would be how how three distinct types of LGDs (I say three because the the Rafeiro and the Estrela are genetically the same pretty much) managed to evolved there. Prior to the Islamic invasion I believe that at some point the LGDs of what is now Portugal and Spain, where of the same basic root stock and landrace, mutually crossbreeding to each other...but post Christian succession the LGDs on the Spanish side (due to the trashumancia movements as I mentioned above) they have assimilated with those left by the moors, considerably altering their DNA but apparently having little impact on them in terms of size, coloration and outward appearance. After all, the German Shepherd is genetically speaking quite different from the Malinois and the other Belgian shepherd dog breeds, but it is probable that they still have shared common ancestry like the Spanish and Portuguese LGDs. And after Portugal's independence, I suppose that political boundaries were a factor in the Portuguese not wanting to outcross their LGD stock with those of their Spanish neighbor and vice versa. After all, there was some beef between the two countries. :p

Quite the contrary, actually. The show lines of Spanish mastiff are themselves a recent creation (starting in the later decades of the 20th century) as a result of crosses to English Mastiff, St. Bernard (smooth coat), Neapolitan mastiff, Fila brasileiro and perhaps some of the other giant breeds in the mix. This is something that is very little known and has been kept secrete from the general public. The blood of the aboriginal SM (LGD landrace that still exists in Spain but its numbers are falling) flows in its veins but it is in many respects only an imitation/wannabe of its original namesake... I do not consider them the same dog at all. Anyone who claims the show type represents the "original" "pure" stock are just repeating a BIG lie!! Even the now much coveted Abelgas line of SM shows evidence of ancestry from show lineages, though appears to have been outcrossed back to aboriginal type mastines making them lighter framed, leggier, more agile, healthier, less skin and more working/guarding instinct than many straight show-line SMs. You are right about one thing, that the show-bred SM has also resulted from intensive line breeding and inbreeding to homogenize breed type and exaggerate desired traits. Hence why the show type SM is riddled with so many problems and such short life span.

 now that were on portuguese breeds and you seem very knolegable  I 'believe ' I have conected the fila  . As a direct  decendant  of   get this Rafeiro do Alentejo,..  lol  fila people hate me for sugesting  this  but the dogs mirror each othere  early fila were short coated  rafeiro same bones structure  job and colors markings and temperment and brazil was a portuguse coloney the people still speake it  and found records   where the were shiped to brazil to work on farms .  Were was the first filas found   yep you gussed it . .. 

I agree. Thought I would mention that I myself am loathed by a handful of "Spanish Mastiff" fanatics for suggesting that their breed is a modern cocktail breed and for openly showing proof of how drastically the breed has been altered from its former self in the past 3-4 decades.