A Grammar of the Ancient Egyptian Pyramid Texts is designed as a six-volume study of the earliest comprehensive corpus of ancient Egyptian texts, inscribed in the pyramids of five pharaohs of the Old Kingdom (ca. 2325-2150 BC) and several of their queens. The first volume, devoted to the earliest corpus, that of Unis, is based on a database that allows for detailed analysis of the orthography of the texts and every aspect of their grammar; it includes a complete hieroglyphic lexicon of the texts and a consecutive transcription and translation on facing pages. The grammatical analysis incorporates both the most recent advances in the understanding of Egyptian grammar and a few new interpretations published here for the first time.