Dom is a sword for hire located in Flea Bottom. He is a former member of a group of young thieves named The Fleas.
Dom is among the handful of Fleas who confronted Cleos Baratheon in the streets of Flea Bottom, suspecting him of being in a rival street gang led by a boy named Brave Ben. Cleos managed to scare them off with his castle-forged steel.
When Dom and several others witnessed Cleos killing Brave Ben they invited him to join the Fleas. They set him on the task of robbing a septon and when he completed it they invited him to their hideaway, Sanctuary, located under a burned-down pot-shop in Flea Bottom.
During his time with the Fleas, Dom tought Cleos how to cut a purse unnoticed.
Dom was among the Fleas who managed to flee Sanctuary before the gold cloaks descended upon it.
There are whispers of a sword for hire named Dom within King's Landing, working out of the burned-out pot-shop that once housed Sanctuary.
“There’s a man. A sword for hire. He goes by the name of Dom. If you can afford him he does good work, quiet work. He has no love for the goldcloaks and would not double cross you as some others would.” - Wat speaking to Larence