(Κλεόμβροτος), son of Anaxandrides, king of Sparta, brother of Dorieus and Leonidas, and half-brother of Cleomenes. (Hdt. 5.41.) He became regent after the battle of Thermopylae, B. C. 480, for Pleistarchus, infant son of Leonidas, and in this capacity was at the head of the Peloponnesian troops who at the time of the battle of Salamis were engaged in fortifying the isthmus (Hdt. 8.71.) The work was renewed in the following spring, till deserted for the commencement of the campaign of Plataea. Whether Cleombrotus was this second time engaged in it cannot be gathered with certainty from the expression of Herodotus (9.10), " that he died shortly after leading home his forces from the Isthmus in consequence of an eclipse of the sun." Yet the date of that eclipse, Oct. 2nd, seems to fix his death to the end of B. C. 480 (thus Müller, Prolegom. p. 409), nor is the language of Herodotus very favourable to Thirlwall's hypothesis, according to which, with Clinton (F. H. ii. p. 209), he places it early in 479. (Hist. of Greece, ii. p. 328.) He left two sons,--the noted Pausanias, who succeeded him as regent, and Nicomedes. (Thuc. 1.107.)