The first successful attempts at deciphering the Brahmi Script were made in 1836 by Christian Lassen, who used a bilingual Greek – Brahmi coin of Indo – Greek King Agathocles to correctly identify several Brahmi letters. The task was then completed by James Prinsep, who was able to identify the rest of the Brahmi characters, with the help of Major Alexander Cunningham. Lassen used the bilingual Greek – Brahmi coinage of Indo Greek kings Agathocles and Pantaleon to correctly decipher the Brahmi Script. Announcement by James Prinsep of the secure decipherement of the first Brahmi letters by Lassen in the Journal of the Asiatic Society of Bengal, in 1836.

Identical regnal names Agathuklayesa (Brahmi: WMNEEMONENBN) and Agathokles (Greek: ATA©OKAEOY) on a bilingual coin of Agathocles, used by Christian Lassen to decipher
securely the first Brahmi letters.

Kharoshthi

He also was one of the first scholars in Europe who took up, with signal success, the decipherment of the newly discovered Bactrian, Indo-Greek and Indo-Scythian coins with Kharoshthi Legends, which furnished him the materials for Zur Geschichte der griechischen und indoskythsschen
Könige in Bakterien, Kabul, and Indien (1838). In this, he closely followed the pioneering work of James Prinsep
(1835), and Carl Ludwig Grotefend (1836). He contemplated bringing out a critical edition of the Vendidad, but, after publishing the first five fargards (1852), he felt that his whole energies were required for the successful accomplishment of the great undertaking of his life-his Indische Altertumskunde. In this work – completed in four volumes, published respectively in 1847 (2nd ed. 1867), 1849 (2nd ed. 1874), 1858 and 1861 – which forms one of the greatest monuments of untiring industry and
critical scholarship, everything that could be gathered from native and foreign sources, relative to the political, social and intellectual development of India. He was elected a Foreign Honorary Member of the American Academy of Arts and Sciences in 1868.