Lykurgus is the son of Herakles and Toxikrate who is one the daughters of King Thespius. During his stay in the court of King Thespius Herakles impregnated 49 out of the 50 Thespius' daughters including Toxikrate who he lay with one night. The result of that particular encounter was Lykurgus.
Spouse or Lovers
"by Toxikrate he [Herakles] had Lykurgus"
- Apollod. Biblioteca 2.7.8