What is in the crypt tomb of the unknown?

What step did the artist use when drawing this pic?

Name this famous sculpture and the time period it is from. under what historical circumstances was it created? what does the sculpture show? this is apollo with battling lapiths and centaurs and it is from the early classical period. before 480 bce, the greeks experienced many conflicts with the persians who threatened their independence, but by 480 bce, the strong armies and navies of the greeks had triumphed over their enemies. because of their great victories, the greeks became very confident and their art emerged with a new style. in this sculpture, apollo stands calming the conflict with his outstretched arm as a display of power.

Which artistic convention was most important to gothic artists