In Twilight, Edward meets Bella Swan, a human girl whose thoughts he is unable to read, and whose blood smells overwhelmingly sweet to him. He fights a growing attraction to her, but after saving her life on several occasions, he succumbs and eventually falls in love with her. Edward admits to Bella that he is a vampire, and that although he retains the physical body of a seventeen-year-old, he was actually born on June 20, 1901. His adoptive father, Carlisle Cullen, transformed him into a vampire in 1918 to prevent him from dying in the Spanish influenza epidemic in Chicago, Illinois. Carlisle instilled in him a sense of morality uncommon in most vampires, and central to his way of life is the refusal to consider humans as food.
However, Edward constantly warns Bella against being with him, perceiving her life to be at risk if she continues to associate with him. Bella's love and confidence in Edward's restraint cause her to ignore his warnings, even after she becomes the vampire James' target. Unlike the Cullen family, who are "vegetarian" vampires (committed to only feeding on animals), James regularly feeds on humans and will not stop until he drinks Bella's blood. With his family's help, Edward is able to save Bella from James' predations, but how to assure Bella's continued safety remains an open question.
In New Moon, Edward's fears for Bella's safety intensify when she cuts her finger and is almost attacked by his brother Jasper. In an attempt to protect her, he convinces her that he no longer loves her, and moves away with his family, leaving Bella heartbroken. Edward finds it difficult to live without Bella, and becomes severely depressed at the prospect of an infinitely long and meaningless life. After he mistakenly learns from his sister Rosalie that Bella has committed suicide, Edward attempts to convince a group of Italian vampires, the Volturi, to kill him. Together with his sister Alice, Bella rushes to Italy and stops Edward before the Volturi can destroy him.
Edward explains why he left, and apologizes to Bella. She eventually forgives him entirely, and they continue with their relationship as though Edward had never left, with the exception that Bella has ties that cannot be broken with a werewolf named Jacob Black. Bella successfully seeks the support of Edward's family on turning her into a vampire. While Edward is furious at the prospect, he later agrees to change her himself if she agrees to marry him first.