The Aṣṭādhyāyī of Pāṇini (c. 4th century BC in Ancient India), is often cited as an example of a premodern work that approaches the sophistication of a modern syntactic theory (as works on grammar were written long before modern syntax came about). In the West, the school of thought that came to be known as "traditional grammar" began with the work of Dionysius Thrax.