Xenophon 
On Horsemanship [PDF ebook] 

Xenophon the Athenian was born 431 B.C. He was a pupil of Socrates. He marched with the Spartans, and was exiled from Athens. Sparta gave him land and property in Scillus, where he lived for many years before having to move once more, to settle in Corinth. He died in 354 B.C.
On Horsemanship advises the reader on how to buy a good horse, and how to raise it to be either a war horse or show horse. Xenophon ends with some words on military equipment for a cavalryman.