This book offers a new analysis of the hypomnema, a type of document in Greek papyri from Egypt opening with the formula to A from B (τῷ δεῖνι παρὰ τοῦ δεῖνος) and transmitting information between an addressee B and a sender A. It first looks at the origin of the type, then at its specialisation in a specific form of communication with the administration, and finally at the impact of the Roman conquest of Egypt on the corpus. The focus lies on the materiality and formulas of the documents, and on the scribal choices behind their production, and crosses the typology of Greek documentary papyri, the analysis of the materiality of handwritten texts, and the interpretation of formulaic elements in ancient texts and epistolography. By doing so, this research contributes to a cultural history of scribal practices in Ptolemaic and Roman Egypt (third century BCE – first century CE). It is relevant for historians focusing on Greek documentary texts (papyri and inscriptions), classical epistolography practices and textual typologies, material studies of handwritten texts, the cultural history of text production and scribal practices, Hellenistic history, the impact of the Roman conquest on local realities, the history of ancient Law.