Xanthus is described as beautiful, majestic, fierce, and black horse.
Xanthus was given to King Peleus of Phtia as a wedding gift from Poseidon when Peleus married Thetis, the Ocean goddess. They were then given to Peleus’ son, Achilles, in the Trojan War.
Xanthus is the offspring of the west wind, Zephyrus, and the harpy Podarge. He also has one brother whose name is Balius.
In the Trojan War Xanthus and his brother, Balius, were the horses who pulled Achilles chariot. It is stated that Achilles best friend, Patroclus, was the only person to fully control them and Achilles allowed him to ride into battle with them. Achilles warned Patroclus not to go too far into battle and Patroclus ignored him and ended up getting killed. Xanthus and his brother grieved for his death and soon after given the power to speak [no one really knows which god]. The god that gave him these powers told him to go tell Achilles that Patroclus was killed by a god that so would he. Achilles rebuked the horses for not protecting when told Patroclus was killed and upon Xanthus finishing his message he was then struck dumb.
Xanthus was given the power of speech by the gods.
There is a horse ranch that is named after Xanthus.
"Xanthus." Encyclopedia Mythica. 2013. Encyclopedia Mythica Online.
11 Apr. 2013 <http://www.pantheon.org/articles/x/xanthus.html>.
"Balius and Xanthus." Wikipedia. Wikimedia Foundation, 23 Mar. 2013. Web. 11 Apr. 2013.