Alcmenes in Wikipedia
Alcmenes (Greek: Ἀλκμένης) or Alcamenes, Alkamenos, was the king of Sparta, of the Agiad dynasty, from c. 740 to c. 700 BC. 
According to Pausanias, he was a commander in the night-expedition against Ampheia, which began the First Messenian War, but died before its 4th year. In his reign Helos was taken, a place near the mouth of the Eurotas, the last independent hold most likely of the old Achaean population, and the supposed origin of the term "helot".
He succeeded his father Teleclus and was succeeded by Polydorus.