Below you will find a very nice article written by David Frawley and after that we see what Srila Prabhupada our Acharya says in the matter. I think you will find that it will make for a very nice read!
One of the main ideas used to interpret—and generally devalue—the ancient history of India is the theory of the Aryan invasion. According to this account, India was invaded and conquered by nomadic light-skinned Indo-European tribes from Central Asia around 1500-1000 BC, who overthrew an earlier and more advanced dark-skinned Dravidian civilization from which they took most of what later became Hindu culture. This so-called pre-Aryan civilization is said to be evidenced by the large urban ruins of what has been called the ‘Indus valley culture’ (as most of its initial sites were on the Indus river). The war between the powers of light and darkness, a prevalent idea in ancient Aryan Vedic scriptures, was thus interpreted to refer to this war between light and dark- skinned peoples. The Aryan invasion theory thus turned the ‘Vedas’, the original scriptures of ancient India and the Indo-Aryans, into little more than primitive poems of uncivilized plunderers.
This idea – totally foreign to the history of India, whether north or south – has become almost an unquestioned truth in the interpretation of ancient history. Today, after nearly all the reasons for its supposed validity have been refuted, even major Western scholars are at last beginning to call it in question.
In this article we will summarize the main points that have arisen. This is a complex subject that I have dealt with in depth in my book ‘Gods, Sages and Kings: Vedic Secrets of Ancient Civilization’, for those interested in further examination of the subject.