Side A: Theseus and Poseidon clasp hands. Nereus and Amphitrite on left, Nereid on right; Side B: bearded man and three youths, one playing the kithara.
This majestic vase shows how Theseus visited the palace of his divine father Poseidon and was crowned by Poseidon's consort Amphitrite (Bacchylides 16:97).