The Oldest Depiction of Kṛṣṇa (01/16/13)
There was once a big book written by BP Banerjee (Head of National Museum at Delhi]) called “Krishna in Indian Art.” We had this book as a reference at the time of writing “Vaishnava India.” In that book Banerjee traces the earliest examples of Kṛṣṇa in Indian art. If you can find that book you will find a lot of information that you are looking for.
Otherwise the Deities of Kṛṣṇa in Vṛndāvana established by the grandson of Lord Kṛṣṇa are the earliest examples of depictions of the form of Kṛṣṇa.
Although there are thousands of pictures of Kṛṣṇa, none of them actually look exactly like Kṛṣṇa. All the painting that exist of Kṛṣṇa all look different, but with defining similarities. The śāstra describes the general appearance of Kṛṣṇa, but from those describtions only a general idea can be drawn or painted with paper, pen and ink. One reason for this is that there is no color in the material world that properly represents ‘śyāma’. Once Śrīla Śrīdhara Mahārāja was asked the question, “Which color Deity of Kṛṣṇa is closest to his actual color – the white Deities such as in New York Iskcon, or the black Deities such as those more common in India?”
Śrīdhara Mahārāja answered that neither black or white is any closer to the color of Kṛṣṇa because these are material colors and concepts, whereas Kṛṣṇa’s color is transcendental to both black and white.
Another example is Lord Jagannātha who is totally Kṛṣṇa, but actually looks nothing like Kṛṣṇa — yet He is Kṛṣṇa and is recognized by His pure devotees. The Buddhists once ruled Jagannātha’s temple for close to 500 years, but they did not recognize Him as Kṛṣṇa. They saw him as Ādi-Buddha.
In any case, our sampradāya does not place much emphasis on paintings of Kṛṣṇa etc. In fact, most of the paintings of Kṛṣṇa found in India are made by Hindus, not Vaiṣṇavas. Many are even made by sahajiyās.
In Vṛndavana there are some temples that claim to have very old image paintings of Kṛṣṇa that came about by some miracle or other, but these are for the most part not given any importance by our ācāryas. The stories about the paintings are usually fabrications to draw more pilgrims [$].
Apart from the Deities of Kṛṣṇa in Vṛndāvana established by the grandson of Kṛṣṇa, the next oldest imagery of Kṛṣṇa is that of the images of Kṛṣṇa and Balarāma found on Greek coins minted shortly after Alexander the Great’s invasion of India around 350 BCE.
Rādhārāṇī wears a locket on her neck with a picture of Kṛṣṇa in it. So ontologically this is probably the first painting of Kṛṣṇa, but it has never been seen by any other than her eternal associates. Similarly Kṛṣṇa wears a locket that has Rādhārāṇī’s picture in it.
All the best.