Like any successful currency, the tetradrachms from ancient Athens – the so-called 'owls' – distinguished themselves by stability and continuity. Apart from some small details, the motifs of the goddess Athena on the obverse and the owl on the reverse remained unchanged over hundreds of years. Not even the style developed; even at the time of the greatest creative phase of classical Greek art, Athena remained archaic. The most distinct indication for this is Athena's eye, which was rendered in the typically archaic front view on a profile head. This only changed at the beginning of the 4th century BC; from now on, the eye of Athena was correctly drawn in profile. Then, the image froze again until the 3rd century BC.