Lycurgus (also Lykurgos, Lykourgos) was a mythological king of the Edoni in Thrace, and the son of Dryas, the "oak". He banned the cult of Dionysus. When Lycurgus heard that Dionysus was in his kingdom, he imprisoned Dionysus' followers, the Maenads. Dionysus fled, taking refuge with Thetis the sea nymph. Dionysus then sent a drought to Thrace.
Going insane, Lycurgus mistook his son for a mature trunk of ivy, which is holy to Dionysus, and killed him, pruning away his nose and ears, fingers and toes. Dionysus decreed that the land would stay dry and barren as long as Lycurgus was left unpunished for his injustice, so his people had him dismembered by wild horses. With Lycurgus dead, Dionysus lifted the curse.
In some versions the story of Lycurgus and his punishment by Dionysus is placed in Arabia rather than in Thrace. The tragedian Aeschylus, in a lost play, depicted Lycurgus as a beer-drinker and hence a natural opponent of the wine god. There is a further reference to Lycurgus in Sophocles' Antigone in the Chorus' ode after Antigone is taken away (960 in the Greek text).
In Homer's Iliad, an older source than Aeschylus, Dryas is not the son of Lycurgus, but the father, and Lycurgus' punishment for his disrespect towards the gods, particularly Dionysus, is blindness inflicted by Zeus followed not long after by death.
A king of Thrace, who, when Bacchus was passing through his country, assailed him so furiously that the god was obliged to take refuge with Thetis. Bacchus avenged himself by driving Lycurgus mad, and the latter thereupon killed his own son Dryas with a blow of an axe, taking him for a vine-branch. The land became, in consequence, sterile; and his subjects, having been informed by an oracle that it would not regain its fertility until the monarch was put to death, bound Lycurgus, and left him on Mount Pangaeus, where he was destroyed by wild horses (Apollod. iii.5.1).