Brego was named after a king, and was stabled at Edoras, and had also gone crazy.
With sometime, Aragorn calmed him down and set him free.
When Aragorn fell down a cliff, being stuck to an orc's saddle, he fell down with the warg.
Brego found him, and laid down next to Aragorn and Aragorn managed to grab a hold on his mane, and rode him back to Helm's Deep. On the way, Aragorn had seen at least ten thousand Uruk-Hai heading towards Helm's Deep. Brego galloped back to Helm's Deep, with Aragorn.
Aragorn rode Brego in Pelennor Fields and Helm's Deep. After the war of Pelennor Fields, Aragorn led the group of men in towards the battle, on Brego, then later on foot.
Brego is played by a horse named, Uraeus
Viggo Mortensen (Aragorn) bought the horse and also bought Kenny (Hasufel)
Uraeus is a 16.1 hand high dark bay warmblood stallion.
Uraeus is up for stud