There were no Aryans or Dravidians. Both were inventions of the Europeans.In the 17th and 18th century the European Indologists such as Voltair (1694-1778) and Schopenhauer (1788-1860) were more positive about India because the translation of Upanishads, Yoga Vashista, Bagavad Gita all had reached Europe from Persia, through the translation done by Dara Shiko. In the 18th century, scholars in Europe discovered that their languages were closely connected to the Sanskrit language. The Sanskrit language was older, more sophisticated than the languages they spoke. It was not only older than the Germanic and European languages, but also older than Greek, Latin, Persian etc. Confronted with that some of them felt Sanskrit was the mother of all languages and India was the mother of civilization and western culture. There was lot of interest to learn Sanskrit in Europe and many universities started courses in Sanskrit. . The languages became a symbol of European and German nationalism of the 19th century. Not only that the word Aryan was used to characterize not only the languages but also the group of people who were hypothesized in the beginning as ethnicity, race, predominantly having blonde hair blue eyes. So the Aryan race grew over both languages and ethnicity which involved with Europe, Russia and Germany.
The colonial era in India continued and it became increasingly clear to the western intellectuals that connection to India robbed them of their independence, and also the originality of their own thought. So there was a movement away from that, and some scholars started saying, there was an earlier proto-Indo-European language from which even Sanskrit was derived. From a mother of all languages position Sanskrit was demoted to one of the languages derived from the Proto-Indo- European language. As the colonial era continued, the colonial funded scholars came up with negative view of Indian culture its literature, also its history, and its antiquity, the most known was Max Mueller. In their examination of the Indian teaching, they tried to find out what was the oldest layer of the Indian thought. When they found out the oldest layer of the Indian thought they came to the conclusion that it was not Indian. And they brought in methods of interpretation which were from outside India, even contrary to what the Indian tradition said. Their main focus was the older Vedic text, the Rig Veda, and their main tools of approaching Rig Veda, was their own tools of comparing European mythology, and linguistic studies. Their conclusion was that Vedas resembled the older folk literature of Europe and it must have been developed in Europe or central Asia, brought in and imposed upon the people of India.
The Vedas were taken out of India and reinterpreted in a way to show that they were inferior to the Bible and European mythologies too. The traditional means in interpreting the Vedic text through Upanishads, through Brahamanas through spiritual meanings and even through literature were rejected. Along with the Proto-Indo-European idea, these languages could not have risen in India, must have come from central Asia and their original culture would have been primitive nomadic people, later warrior people, who spread their language with horses and chariots. This theory did not develop over night and it had political ramification and colonial support.
Monier Williams in his Sanskrit – English dictionary, in the introduction says that he was doing this to show what Indian thought really is and allow people to convert to Christianity and to show superiority of the Christian ideas. At that time there was nothing hidden about these ideas; the colonial agenda, the missionary agenda, the missionary assault on India and rest of the world was in full swing. It had the support from all the churches, the governments and made no qualifications about what they intended to do. They rejected the superiority of Indian culture, rejected the interpretations of the Vedas, and the Indian interpretation of history altogether. They came to the conclusion that India had no history, Indian texts were historically invalid, or they were mixed with mythology. They threw out the whole tradition and pretended that Vedas were something only they could understand and the Hindus could not.
They came to the conclusion that the blonde haired blue eyed people came into India in 1500 BC, civilized, the primitive, culture less, aboriginal type of people. Some of them went further and said that there were no cities in India before the invasion of Alexander and it was the Greeks who civilized India. That was the scenario up into the 20th century. Western, Aryan people came into India and brought in the civilization and in Europe it allowed the German to connect back to their mythology and associate Christianity and Judaism as their origins. Europe equated this glorious Aryan identify, particularly for Germany and India was made an off shoot of that.
Then in the 20th century archeologists lead by Sir John Hubert Marshall (1876-1958) began to find significant ruins in India, largely near the Indus River, which they called the Indus valley civilization. Two main cities they discovered, Mohenjadaro and Harappa. Curiously this dated from the third millennium BC, a thousand or two thousand years earlier than they were willing to allow that civilization had existed in India.
Of course it contradicted their Aryan theory, that it India was civilized then, it was civilized before the Aryans came in. So they reinvented the destroyers of the Indus valley culture and made them from the bringers of civilization to the destroyers of it. Then they renamed it the Aryan Invasion theory, describing it as Aryans coming in, plundering and destroying the existing culture. One of the archeologists Sir Mortimer Wheeler (1890-1976) gathered some skeletons and said that is the proof of Aryans invading and killing everybody. This is how the Aryan Invasion Theory came into existence. The Aryan race was a ghost in the European mind, nothing more nothing less. There were no Aryans and they did not have language. Sanskrit is 100% Indian and there were number of Universities in India starting from 700 BCE. There was scramble from all over Asia and Europe to get educated in in Indian universities. The medium of teaching in these universities was Sanskrit and that is how Sanskrit and its words spread all over Asia and Europe.