Hellenism refers to the spread of Greek culture, language, and ideas that began after the conquests of Alexander the Great in the 4th century BCE. This cultural diffusion influenced various regions, including parts of Egypt, Persia, and India, leading to a blend of Greek and local traditions. The term also describes the period of Greek history and culture that followed the classical era, known as the Hellenistic Period, which lasted until the Roman conquest. During this time, advancements in art, philosophy, and science flourished, with notable figures like Euclid and Archimedes making significant contributions.