The Bacchae killing Pentheus, Casa dei Vettii, Pompeii

In Greek mythology, Pentheus (Πενθεύς) was a king of Thebes, son of the strongest of the Spartes, Echion, and Agave, daughter of Cadmus, the founder of Thebes, and the goddess Harmonia.

Cadmus abdicated in favour of Pentheus because of old age. Pentheus banned the worship of Dionysus, the son of his aunt Semele, and did not allow the women of Cadmeia to join in his rites. Dionysus caused Pentheus' mother and his aunts, Ino and Agave, to rush to Mount Cithaeron (or Mount Parnassus) in a bacchic frenzy. Because of this, Pentheus imprisoned Dionysus, but his chains fell off and the jail doors opened for him.

Dionysus then lured Pentheus out to spy on the bacchic rites. The daughters of Cadmus saw him in a tree and thought him to be a wild animal. Pentheus was pulled down and torn limb from limb by them (sparagmos), causing them to be exiled from Thebes. The name 'Pentheus', as Dionysus and Tiresias both point out, means "'Man of Sorrows'; even his name destines him for tragedy.

Pentheus was succeeded by his uncle Polydorus.

Death of Pentheus, Louvre G445, (Agave and Ino)

Death of Pentheus, Douris ?, 480 BC

The Corinthians had a tradition that the tree in which Pentheus hid was afterwards carved into images of the god Dionysus and worshipped (Pausan. ii. 6, 6). Hence some have tried to connect the story of Pentheus with the primitive tree-worship.