The study of Sanskrit grammar is widely recognized as one of Indias great intellectual traditions. The most famous school of grammar was the one based on Pa?inis A??adhyayi, a work dating from perhaps the fifth or fourth century BC and consisting of approximately four thousand short rules arranged in eight books. Over two millennia scholars produced a huge literature of commentaries to explain how these rules work. Alternative schools were also developed, either to provide easier access to the classical language or to create authoritative texts for groups with distinct religious or social identities. A considerable amount of scholarship was produced by the Pa?inian school between the sixteenth and eighteenth centuries. Two of the most famous scholars from this period were Bhatoji Diksita and Nagesabhatta. The former composed the hugely influential Siddhantakaumudi, a commentary on the A??adhyayi in which Pa?inis rules were radically reordered. Before composing this work, Bhattoji wrote the Sabdakaustubha commentary on the unaltered text of the A??adhyayi. This was a massive work that was perhaps never completed. In his other grammatical works Bhattoji refers readers to the Sabdakaustubha for further details. Nagesabhatta was a pupil of Bhattojis grandson and is often regarded as the last great figure in the tradition of grammatical scholarship. He wrote several authoritative books on grammar, including three celebrated commentaries on Bhattoji's works.