He disregarded the warnings of his mother and ventured south past Archenland and into Calormen, where he was captured and either enslaved by or eventually sold to the Tarkaan Anradin.
Bree developed a very high opinion of himself with only non-talking horses to compare himself to, further enhanced by his status as the prized steed of a Calormene lord and his training as a war charger.
This incident deflates much of Bree's ego, as he feels intense shame for leaving the two females behind while a boy raised as a peasant found the courage to go back.
Bree's shortened name is the same as the town in C. S. Lewis's lifetime friend J. R. R. Tolkien's book The Fellowship of the Ring, where there is an inn called The Prancing Pony.
In Hal Clement's 1953 science fiction novel Mission of Gravity, Bree is the name of the ship captained by the Mesklinite trader Brennan, one of the focal characters of the novel.