Good question!^sanskrit is first spoken in north that doesn't mean its european/central asian ,its the language of early indigenous indians, presently who are living in south and some people in north india.^
Neelakaran,-- Why Nordic or central Asian is to be called Aryan invasion or migration? Was there any race at all as Aryan ? Is it just a label invented by Euro/German to claim Sanskrit as Indo european language? and just to rob Indian antiquity and its past glory?
Aryan is not a race.
The word Aryan supposedly evolved from a Tamil name 'Ariyan'(singular) or 'Ariyar'(plural) which itself evolved from its root word in Tamil 'Ariya'= rare. It is pronounced 'Ariya' with short A sound and Not as Ariyaa.
Evolution of the term 'Aryan':
Once upon a time the Dravidians were settled all over India. One day migration of people from outside India (especially from middle east and Europe) started to happen. They were Caucasian who had white skin, sharp nose, etc and looked different from the native Dravidians hence they called them 'Ariyar' meaning 'Rare people'. Those were the time Caucasians were too small in number in India hence they were referred Rare.
Change of meaning down the course of History:
The immigrant population started to grow and soon they had their own land, established their own empires in India but their name as 'Ariyar' carried on. Soon the word 'Ariyar' started to change its meaning and people used the word to refer immigrants in general or those who do no belong to home land (India). Thus 'Ariyar' became a word which is referring immigrant foreigners.
If Mongols visited India then they too would have been called as 'Ariyar' back then.
About modern 'Aryan':
British did not cook up new history. The immigrants were always referred as 'Ariyar' or 'Ariyan' in India which got corrupted and became 'Aryan'.
Controversies in Sanskrit meaning:
In Sanskrit the term 'Arya' was used to refer noble people whereas the Tamil word 'Ariyan' means rare people, hence the people with rare skills like jugglers or tumblers were called as 'Ariyan' in ancient Tamil kingdom which is also mentioned in the literature. These rare skilled people might have been considered noble hence only in this context there is similarity in meaning in both Tamil and Sanskrit.
Why consider Rarity as Noble?
I can answer this with an example from Chemistry. We know that there are 6 Intert gases. They are also called Rare gases or Noble gases. Noble gas is mere translation of 'Edelgas' which in German means 'Noble gas'.(Germans too have ancestral connection with the immigrant Aryan population).
The accepted reason why they are named Noble gas is -> They did not engage in any of the usual chemical reactions with other elements, and so were "aloof", i.e. seldom found in compounds.
Something that is different from the rest is Noble according to these immigrant population. Hence they called themself Noble because they are different. Likewise The Germans too named the gases Noble because they are Rare and different from the rest.
We can see striking similarity in the mentality of the Aryans here. Because they have same ancestry and hail from same place, same culture, mentality and lifestyle.
Even though all these happened they are still Indians and we cannot call them immigrants anymore. You stay in some other country for 10 years you get the citizenship. These people are part of India for around 6000 years. The Sanskrit credit still goes to India because when they created Sanskrit they must have been already settled in India for at least 1000 years and they have already become Indians when they created Sanskrit.