Willam the Wanderer

"Ser Damon Morrigen proposed a trial by seven. Ser Damon and six of the Faith Militant against the king and his six champions."

- The High Sparrow

Ser Willam the Wanderer was a member of the Faith Militant during the order's revolt against House Targaryen.

Biography
Ser Willam was a knight and and a devotee of the Faith Militant. When newly-crowned King Maegor Targaryen returned to King's Landing, Ser Damon Morrigen challenged the Faith Militant to a Trial by combat to prove his right to rule. They accepted, and the resulting trial of seven pitted Maegor and six of his Kingsguard against Ser Damon and six other champions of the Faith Militant, among whom was Ser Willam. The tales about the resulting confrontation are many, but by the end, of the fourteen men who entered the field only Maegor was left alive.

In the books
In the A Song of Ice and Fire novels, Ser Willam the Wanderer is a member of the Warrior's Sons - one of two military orders that comprises the Faith Militant. In the TV show the Faith Militant is condensed into a single order. Ser Willam was stationed at the King's Landing chapter of the Warrior's Sons, based in the Sept of Remembrance, in 42 AC. He was killed in the trial by seven between the Warrior's Sons and Maegor Targaryen and his Kingsguard.

Along with Ser Damon Morrigen, Ser Willam was the last member of the Warrior's Sons standing against King Maegor Targaryen, all of whose champions had been killed. Both were badly wounded by this point and were then killed by Maegor with the Valyrian steel sword Blackfyre. Before he died, Willam managed to deal a terrible blow to the king's head, which cracked his helm and rendered him senseless, though he survived and emerged as the conflict's only survivor.