Harley was a minor canon of Westminster Abbey, and lead a life of blind servitude and devotion to the Church of England. Over time, however, he grew dissatisfied with allowances in the Abbey. From there on out, his life took a darker turn, and Harley soon joined the Blighters street gang, threatening to destroy Westminster abbey.
The Metropolitan Police Service took an interest in Harley for his criminal activities, as well as his condoning of slave labor. Sergeant Frederick Abberline tasked the Assassins Jacob and Evie Frye with bringing the criminal in.
The twins found Harley outside Westminster Abbey, where they were able to subdue him, lock him in a carriage, and deliver him to Abberline.