Foundation: Book One of the Collegium Chronicles: A Valdemar Novel by Mercedes Lackey

In this chronicle of the early history of Valdemar, a thirteen-year­old orphan named Magpie escapes a life of slavery in the gem mines when he is chosen by one of the magical Companion horses of Valdemar to be trained as a Herald. Thrust into the center of a legend in the making, Magpie discovers talents he never knew he had and witnesses the founding of the great Heralds' Collegium.