The ancient Indian script, 'Brahmi', was deciphered by James Princep. He was a key figure in the study of Indian epigraphy and archaeology.
Princep's work in the 1830s involved comparing inscriptions found on coins and pillars, particularly those from the Maurya period. His meticulous research led to the gradual understanding of the Brahmi script, which had been unreadable for centuries.
This decipherment opened up a vast amount of historical and cultural information from ancient India, significantly advancing the study of Indian history.
Therefore, the correct answer is James Princep.