The north frieze as well as the south one depicts a battle of Greeks against Persians, and it is the earliest example of sculpture commemorative of specific historical events. The relief of the west wall represents a battle between Greeks and other Greeks (perhaps a reference to the ongoing Peloponnesian war), while the East frieze above the colonnade of the entrance shows a number of gods and deities in various stages of activity.
The art itself is indicative of a developing style that had mastered accurate representation and was now content with exploring other aesthetic issues. The figures are elongated wearing drapery that not only clothes them but with its deep folds creates a rhythmic visual pattern. The bodies are contorted in extreme, almost awkward poses bestowing a degree of expressionist anxiety to the idealized figures. These stylistic innovations act as a prelude to the development of the soon to be realized Hellenistic art.
Also see: Pictures of the Athena Nike Frieze