Pāṇini’s monumental grammar Aṣṭādhyāyī, embodied in nearly 4000 cryptic statements called sūtra-s, remains incomprehensible without the aid of detailed explanations and commentaries. The Kāśikāvṛtti, a Sanskrit work ascribed to Jayāditya and Vāmana of about the 7th century CE, stands out among the great mass of commentarial literature as the only exposition that covers all the sūtra-s in their Pāṇinian sequence. It is marked by its lucid explanations, simplicity of style, abundance of illustrative examples, and a profound awareness of grammatical works that preceded it, like the Mahābhāṣya and Cāndra-Vyākaraṇa. The Kāśikāvṛtti has therefore served as the basic source on which any Aṣṭādhyāyī exposition in any language should rely, up to the present day. The present series, of which this is the first volume, is intended to offer the complete Kāśikā with an accurate English translation and explanation, sources and analysis of the examples, and its possible relation to predecessors in its field. It is hoped that this unabridged and annotated English version will not only bring the whole Kāśikā within the reach of the modern reader, but will generally make Pāṇini’s grammar an interesting journey as well.