Nearly two thousand five hundred years ago, a king called Alexander the Great lived. He was the son of Philip II of Macedonia.

When Alexander was a boy, a magnificent horse for sale was brought to his father's court. The animal was to be sold for thirteen talents. Talents were ancient coins. Many were eager to buy the horse, but none could get close enough to saddle the restless animal. It was wild and impossible to ride.

Alexander pleaded with his father to let him try. Realizing that the horse was terrified of its own shadow, Alexander turned it towards the sun so that its shadow fell behind it. This calmed the horse, and the prince proudly rode away. His father observed this and said, "My son, look for a kingdom worthy of your greatness. Macedonia is too small for you."

That is exactly what Alexander tried to do when he grew up. He fought many battles and always rode Bucephalus (that was the horse’s name). Friendship and trust grew between man and horse. When Bucephalus died of wounds received in battle, Alexander was heartbroken and deeply mourned the loss of his horse. He wished that he had died alongside it.

According to the above passage, what was the name of the horse?