Maegor the Cruel was the third king of the Targaryen dynasty in Westeros, ruling from 157 to 158 AC. He was known for his brutal methods and harsh rule, which earned him the nickname "the Cruel." Maegor was the son of Aegon I Targaryen and Rhaenys Targaryen, and he sought to consolidate power through fear and violence. During his reign, Maegor built the Red Keep in King's Landing and was infamous for executing his enemies, including members of the Faith of the Seven. His reign ended when he died under mysterious circumstances, leading to a power struggle that ultimately resulted in the ascension of his half-brother, Aegon III.