Wikipedia
In Greek legends, Procles (, "the renowned") was one of the Heracleidae, a great-great-great-grandson of Heracles, and a son of Aristodemus and Argia. His twin was Eurysthenes. Together they received the land of Lacedaemon after Cresphontes, Temenus and Aristodemus defeated Tisamenus, the last Achaean king of the Peloponnesus. Procles married Anaxandra, daughter of Thersander, King of Kleonoe, sister of his sister-in-law Lathria, and was the father of Soos and the grandfather of Eurypon, founder of the Eurypontid dynasty of the Kings of Sparta.
The title of archēgetēs, "founding magistrate," was explicitly denied to Eurysthenes and Procles by the later Spartan government on the grounds that they were not founders of a state, but were maintained in their offices by parties of foreigners. Instead the honor was granted to their son and grandson, for which reason the two lines were called the Agiads and the Eurypontids.