This small marble statue is supposed to be a close copy of the enormous cryselephantine (gold and ivory) sculpture of Athena Parthenos made by the sculptor Phidias.
that originally stood in the Parthenon in the mid-5th century. Phidias's original sculpture was reported to be about 12 m. tall (about 40 feet).
This small copy in marble is a little over 3 feet tall.