Age Of The Veda - Aryan Migration Theory
The old Iranian language of Avesta, is very close to Vedic language. Avesta, the old scripture of Zoroastrism (modern day Parsis) is very much like the RigVeda. The Avesthan people and Vedic people called themselves, Aryans (Iranian - airya). Infact, Persian kings, proud of their Aryan origin, named their country Iran, in the aftermath of the Aryan race theory.
The first systematic theory of the relationships between human languages began when Sir William Jones, the Chief Magistrate of Calcutta and the founder of the Asiatic Society, proposed in 1786 that Greek and Latin, the classical languages of Europe, and Sanskrit, the classical language of India, had all descended from a common source (The Third Anniversary Discourse On The Hindus,1786 ). The evidence for this came from both the structure of the languages - Sanskrit grammar has similarities to Greek - and the vocabulary of the languages. Thus, father in English compares to Vater in German, pater in Latin, patêr in Greek, pitr. in Sanskrit, pedar in Persian, etc. On the other hand, father in Arabic is ab, which hardly seems like any of the others. This became the theory of Indo-European languages, and today the hypothetical language that would be the common source for all Indo-European languages (Language Family Tree - Indo-European) is now called Proto-Indo-European.
First it was thought that India was the possible origin of all civilization (Enlightenment scholars like Voltaire). The famous German philosopher Kant placed the origin of mankind in Tibet. Eighteenth century German scholar, Friedrich Schlegel (1772-1829), supposed that a new people had formed itself in northern India, swarmed towards the West, populating Europe. Later it was postulated that the original home of Indo-Europeans was Central Asia, (because of common word roots for winter and snow, but not for rice or ocean, also presence of horse - so the original home must hav been a cold place away from the oceans) and various groups of people migrated south to occupy India and Iran, West to occupy Europe. French writer Arthur de Gobineau (1816-1882) proposed that Eurpean aristocracy was Aryan, peasants were not Aryan and Anti-Semitic ideas against the Jews was born.
German scholar Max Muller (1823-1900), who picked up this prevelent theory, explained that Indo Aryans came to India from north west and conquered the Dravidian people who lived there, pushing them to the south, sometime around 1500 to 1000 B.C. He thought the high castes were Aryan people, while the lower castes non-Aryan (just like it was argued in Erupoe). After the excavations and discovery of Indus valley civilization (Harappa, Mohanjodaro - 1920 AD), Sir Mortimer Wheeler a British archeologist, in 1946 theorized that Aryans invaded the cities of Indus Valley bringing that non-aryan civilization to an end. Aryan Invasion Theory (AIT) became the accepted theory.