"The Hyrulean royal family that perished 100 years ago would sometimes ride atop white horses as a display of their divine right. This white horse may be a descendant of one once ridden by royalty."
The White Horse is a special type of Horse found in Breath of the Wild. There is only one to be found in Hyrule, and it lurks in the lush fields by Safula Hill, in the Ridgeland Region. This horse is a descendant of the horse that once belonged to Zelda, as seen in many of the Memories in the game.
Link must tame this horse and ride it back to the Outskirt Stable in order to complete the side-quest The Royal White Stallion. Upon completion of this, Link will be rewarded with the Royal Saddle and Bridle, which are the only pieces of Horse Armor that this horse can wear.