Labdacus

In Greek mythology, Labdacus was the only son of Polydorus and a king of Thebes. Labdacus was a grandson of Thebes' founder, Cadmus. His mother was Nycteis, daughter of Nycteus. Polydorus died while Labdacus was a young child, leaving Nycteus as his regent, although Lycus soon replaced him in that office.
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[Greek heroic] The king of Thebes, ancestor of Oedipus. His descendants are called the Labdacids.