St. Augustine of Hippo 385-430 AD Educated convert from Manicheeism who became the founder of a distinct Western theology. Philosophical doctrine of Trinity leading to Filioque, Doctrine of original sin and Pelagian controversy leading to Predestinationism and displacement of ascetic theology.
http://archive.org/download/OrthodoxChurchHistory/16-AugustineF_LQ_WEB.mp3