Rhesus. Rhesus is a fictional Thracian king in Iliad, Book X, who fought on the side of Trojans.
Diomedes and Odysseus stole his team of fine horses during a night raid on the Trojan camp. According to Homer, his father was Eioneus who may be connected to the historic Eion in western Thrace, at the mouth of the Strymon, and the port of the later Amphipolis.
Later writers provide Rhesus with a more exotic parentage, claiming that his mother was one of the Muses and his father the river god Strymon. Stephanus of Byzantium mentions the name of Rhesus' sister Sete, who had a son Bithys with Ares.
Rhesus was raised by fountain nymphs and died without engaging in battle. He arrived late to Troy, because his country was attacked by Scythia, right after he received word that the Greeks had attacked Troy.
Dolon, who had gone out to spy on Agamemnon's army for Hector, was caught by Diomedes and Odysseus and proceeded to tell the two Argives about the newest arrivals, Thracians under the leadership of Rhesus. Dolon explained that Rhesus had the finest horses, as well as huge, golden armor that was suitable for gods rather than mortals. Because of Dolon's cowardice, Rhesus met his demise without ever getting the chance to defend himself or Troy. When the Thracians were sleeping, Diomedes and Odysseus attacked the camp in the dead of night, killing Rhesus in his tent and stealing his famous steeds.