(Ἀλκαμένης), king of Sparta, 10th of the Agids, son of Teleclus, commanded, according to Pausanias, in the night-expedition against Ampheia, which commenced the first Messenian war, but died before its 4th year. This would fix the 38 years assigned him by Apollodorus, about 779 to 742 B. C. 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. (Paus. 3.2.7, 4.4.3, 5.3 ; Hdt. 7.204; Plut. Apophth. Lac.)