Constable Jack Thornton was a Mountie of the RCMP an honourable, responsible partner to Elizabeth
Thatcher. His father, Thomas Thornton, was a Mountie who was killed in the line of duty. His younger brother, Tom, is a troublemaker, and at one point pursued a relationship with Julie Thatcher, Elizabeth's sister. His mother is still alive and still in his life, though not as much as she hopes. Despite having big plans in Cape Fullerton, Jack was reassigned to Coal Valley (now Hope Valley) a little while after the accident at the mine at the request of William Thatcher, Elizabeth's father. Originally he sent a demand to his superiors to leave, but eventually, Coal (Hope) Valley grew on him. After a five-season long romance, Jack married Elizabeth in a beautiful wedding. After only a day or so of marriage, Jack got an assignment to train other mounties, forcing him to leave his new bride. Tragically, a landslide occurred a few weeks into the training, and Jack pushed two of his men out of the way, sacrificing himself. His death was traumatizing and he left behind his young wife, Elizabeth, who is expecting the couple's first child.