The Holy Hundred is a group of one hundred soldiers sworn to the Faith of the Seven.
The Holy Hundred, led by Laenor Velaryon, fought in the van under Nathaniel Arryn at the Kingswood in order for Laenor to prove fealty to King Damon Lannister after being imprisoned for suggesting that he reinstate the Faith Militant.
After the victory at Stonehelm, Laenor was given a position on the Small Council as Lord Spiritual. When Aeslyn Targaryen was arrested and tried for infidelity, he aided her in escaping the keep. After the King disappeared in Dorne, Loren Lannister had Laenor tortured and sent to the Wall for his role in the trial. Laenor managed to escape his escort North and vanished, but the Holy Hundred were scattered.
Laenor resurfaced in the Riverlands, where he was leading a new Holy Hundred, assisting the smallfolk against bandits. After capturing Orys Connington and holding him for ransom, Nathaniel Arryn led men to defeat them and scatter them once more.