Jules Blackthorn is a fictional character from the popular book series, "The Mortal Instruments," written by Cassandra Clare. He is a Shadowhunter, a human with angelic blood, tasked with protecting the world from demons and other supernatural threats. Jules is known for his strong sense of justice and loyalty to his friends and family. In the series, Jules is part of the Blackthorn family, which plays a significant role in the Shadowhunter world. His character is often depicted as brave and resourceful, navigating the challenges of being a young Shadowhunter while dealing with personal struggles and relationships, particularly with his siblings and friends.