I think there is a misconception about the white race due to different theorys and no real hard evidence of which theorys are more accurate over the others, so heres how i see it from the research i've done on the topic and after all the different theorys i've seen
I believe the very first inhabitants of Europe were alpines which were neanderthals who had adapted to the climate, however then the nordics (the first and true caucasians, armenoids if u prefer) were adapted around the caucasus region (i believe they were originally negroids, due to blacks occupying this area) and the nordics were a fierce and mighty tribe who then invaded all of europe, middle east, north africa.
Now these first nordics (armenoids) had long heads, narrow faces, aquiline noses, cleft chins and sunken in eyes, blue eyes and straight blonde hair, however when migrating to europe and conquering most of the land, they then mixed with the alpines (who only occupied certain areas of europe and not all over) and due to alpines having smaller button noses and larger heads and jaws the europeans got smaller noses and the blue eyes blonde gene was dominant over neanderthal (original alpines) features causing basically the whole of europe to be blonde haired and blue with more nordic features apart from areas like germany and scandanavia where excessive traces of alpine skulls are still very present.
now not all the nordics went to europe, some went down to persia and went as far as india mixing with the native mongoloid races of those regions, and some went down to arabia and then north africa. This is what caused what we call today middle easterns (arabids) which is a mix of the ancient nordics with the negroid semites.
then basically you go from there, the invasions and conquering began of differnt mixtures of the white race, the arabids invaded turkey which had excessive alpine inhabitants, which then got invaded again by persians(iranids) which were more pure nordics that adapted to the persian climate wit slight admixtures of mongoloid from the natives and partial negroid from the arabid invaders. then the arabids invaded north africa which were berbers (ancient nordics mixed with partial negroid) which then invaded southern europe which at the time would have been pure nordics (blonde hair and blue eyes) with of course slight admixtures of alpine, then the black slaves were introduced to all these regions which caused even higher negroid admixture within the north african arabs, the southern europeans and more recently even areas of western europe such as france and england who had black slaves after sea exploration.
Now you may think this makes no sense or you completely disagree but this is what i believe from my research and own observation e.g. i live in a country with plenty of arabian people and looking at them i can see the ancient nordics (big/aquiline nose, some have light hair and/or eyes, straight hair, eyes quite close together) and i can see the negroid (fat nose, frizzy hair, eyes further apart, dark hair & eyes, obviously that became the majority due to blue eyes and blonde hair being recessive) so if your in doubt on my theory then have a good look at certain people and their background or ethnicity and my theory might make abit more sense or you may be able to think up your own theory.
In any case we'll never have hard proof of how the white race and all the sub-categoys truely evolved we can only assume and create or own different theorys from what we've discovered about history and bones etc, but most of the ideas/theorys of races comes from William Z. Ripley due to him being the first to think this out so far as writting a book as old as 1899, however with technology today, if we were to get another Ripley, we could possibley figure the different races, stages of evolution and inter-racial mixtures once and for all of all the racial types of the world and how they all came to be.