Baldwin IV of Jerusalem was the son of Amalric I of Jerusalem and Agnes of Courtenay. He was crowned in 1174
but was only 13 years old at the time so a regent had to rule for him until he turned 15 years old. After he was crowned, it became evident he had leprosy although there were signs of the disease when he was 9 years old. He led the Franks in the Battle of Montgisard against Saladin and was victorious. However, his leprosy got worse and he had his nephew Baldwin V of Jerusalem crowned as co-king. He died in 1185. No historical account of his life mentions him wearing any sort of mask to cover his leprous face.