Early christianity is a research field and academic concept focused on the formative period of the Christian movement, typically spanning from its origins in first-century Judaism through its development into a distinct religion by roughly the fourth century CE. As an area of scholarly inquiry, it investigates the historical Jesus, the emergence and diversity of early Christian communities, the composition and transmission of foundational texts, the development of early Christian beliefs and practices, and the social, cultural, and political contexts of its spread within the Greco-Roman world and beyond. This field is characterized by critical engagement with diverse primary sources (textual, archaeological, epigraphical), interdisciplinary methodologies, and an emphasis on the heterogeneity and evolution within the early Christian landscape, holding significance for understanding the foundations of Christianity and its enduring historical and cultural impact.