Blood Red Horse (The deGranville Triliogy)

You need three things to become a brave and noble knight:
A warhorse.
A fair maiden.
A just cause.
Will has a horse--a small chestnut stallion with a white blaze in his brow. Ellie is a fair maiden, but she's supposed to marry Will's older brother, Gavin. And as for the cause, King Richard is calling for a Crusade. The Knights of England must go to the Holy Land to fight.
Will and Gavin will go. Blood will be shed. Lives will be taken. But through it all, two things will be constant--Ellie, and a blood-red horse called Hosanna. . . .