In The Making of the Trinity, Jake Brancatella examines the historical formation of Trinitarian doctrine from the New Testament period through the major debates of the early Church. Through close engagement with early Christian writings, patristic theology, and the controversies surrounding figures such as Justin Martyr, Irenaeus, Tertullian, Origen, Eusebius of Caesarea, and Athanasius, this book explores how Christian thinkers understood the Father, the Son, and the Holy Spirit before the doctrine was formally defined in later orthodoxy. Rather than assuming later creeds as the starting point, this study asks what the earliest sources actually say. It investigates questions of divine hierarchy, Christ’s relationship to the Father, the development of Logos theology, the role of the Holy Spirit, and the gradual emergence of Nicene and post-Nicene formulations. The Making of the Trinity presents a carefully documented challenge to simplified narratives of doctrinal continuity. It argues that the doctrine of the Trinity did not appear fully formed at the beginning of Christianity, but developed through centuries of debate, reinterpretation, and controversy. Accessible yet rigorous, this book is written for readers interested in early Christianity, Church history, patristic studies, Islamic-Christian dialogue, and the historical development of doctrine.