Neoplatonism emerged in the 3rd century CE, synthesizing Platonic philosophy with other intellectual and religious traditions. It developed during the Roman Empire, drawing from Plato's metaphysics and ethics, as well as Aristotelian, Stoic, and Pythagorean ideas. Key figures like Plotinus, Porphyry, and Proclus shaped Neoplatonism's core concepts. These include the idea of the One as the ultimate source of reality, a hierarchical universe, and the soul's ascent to union with the divine through contemplation and virtue.