Karthuil was born in Gondor, but was taken across the lands to Eriador after his village was destroyed due to wild men. His mother and father died during the journey due to an orc raid and Karthuil was left an orphan. The others that fled with his family brought him to Bree, but left him there. Karthuil grew up alone, but he raised himself and taught himself many things. Learning from the streets, alleys, and books at the local scholar's workplace. He learned many tricks and techniques from living in poverty. Karthuil learned to steal and the ways of subterfuge, but he only stole from those who were malicious and selfish. Karthuil grew to be a cunning, strong man with the heart and thirst of a lion.

Late one night when Karthuil was fifteen years of age, a passing lord came into Bree for the night. A storm raged outside, the rain pelting the ground with such force that it created a howl that dwarfed even the wolves. The lord ordered the finest room in the Prancing Pony, but was too tired to place his bodyguards outside his door. Karthuil saw the bodyguards order several round of ale and they soon became drunk. While they were conversing, the bodyguards slipped out that their lord killed several of his mean for not paying taxes. Karthuil laughed inwardly and creeped up to the lord's room. He entered soundlessly; a feat learned from stalking the rats in the alleys to feed upon. The lord was imbecilic enough to leave his possessions lying on the floor. Karthuil grabbed the fine long bow and the leather armour crumpled next to it. Without any disturbance, Karthuil left the Prancing Pony while the storm began to die down and hid his stolen items in a small chest where he placed in the alley. The chest was positioned so that no man could find it. The sun had not risen yet, so Karthuil decided to play one last trick on the murderous lord. He lead the lord's horses outside of Bree and let them loose into the wild. The next day, the lord grew furious and demanded recompense for the lost horses. He received none, eventually paying twelve gold for horses for his men and himself. A suiting price to a suiting lord.

Karthuil began to develop his skills with the bow; training every day with it. When he deemed himself proficient enough he began to hunt animals to feed himself and gain what coin he could. While this lifestyle was not luxurious, it was better than feasting off the bony rats in the alleys and drinking their blood or dirty water. There was a hard life ahead of him, but when had it ever not been?