What event marked the end of the classical period of greek history?

The end of the classical period of Greek history is often marked by the conquest of Greece by Philip II of Macedon in 338 BCE, following the Battle of Chaeronea. This event signified the decline of the city-states' independence and the rise of Macedonian power, which led to the eventual spread of Hellenistic culture under Alexander the great. The classical period is generally considered to have spanned from the 5th to the late 4th century BCE.