Grail Knights

Every model in a unit of Grail Knights can issue and accept challenges as if they were champions.

For generations, the Bretonnian Warhorse has been bred to bear the weight of a fully armoured knight. Bretonnian Warhorses do not suffer any movement penalties for being barded.

Knights with the Grail Vow are Immune to Psychology, and cannot be joined by characters that have the Knight's Vow or the Questing Vow.
Any model with the Grail Vow always starts the game with the Blessing of the Lady, regardless of whether or not the Bretonnian army prays. All attacks made by models with the Grail Vow count as magical, though this does not affect the Knight's mount.