Jasper Hale (born Jasper Whitlock) is one of the few surviving vampires of the Southern vampire wars, who later joined the Olympic Coven. He is the husband of Alice Cullen and the adoptive son of Carlisle and Esme Cullen, as well as the adoptive brother of Rosalie Hale, Emmett and Edward Cullen. Jasper is also the adoptive brother-in-law of Bella Swan and the adoptive uncle of Renesmee Cullen.
Jasper Whitlock joined the Confederate Army before he turned 19, using his way of persuasion. In the following 2 years, he was promoted to major in the army and became the youngest major in Texas. After evacuating women and children there, he rode on his way back to Galveston and met the vampires, Maria, Lucy and Nettie, who had recently lost their respective territories to other covens. Maria knew from his suit that he was in the military and changed him into a vampire in the hopes of utilizing his training and experience to create an efficient vampire army. When he became a vampire, Jasper gained the ability to feel and manipulate people's emotions which was very useful in controlling the younger newborns. Jasper commanded Maria's newborn army that participated in the Southern vampire wars. Since Maria wouldn't keep vampires after the first year of their transformations, Jasper was responsible for disposing of them, something he felt remorseful of because he could feel their pain when he killed them just as much as he could feel the pain of his human victims. Jasper and other newborns helped Maria reclaim both her territory and her dominance over others. Nettie and Lucy gained territories of their own, but when they tried to rebel against Maria, Jasper sensed their malevolent emotions and teamed up with Maria to kill them. Jasper and Maria seemingly shared a short romantic relationship but she never got over her deceased mate. Over time, the pain and cruelty of such existence depressed him to no end. While in the army, he befriended a newborn named Peter, whom he persuaded Maria to keep because of his advanced combat skills and kindred spirit.
When Peter ran off with Charlotte, a newborn that they were supposed to kill, Jasper allowed them to escape. After this incident, Maria's feelings for him changed: he could sense how fearful - and somewhat mistrustful - she was toward him, and knew that she would plot a way to destroy him. He began planning how to destroy her first, despite his reluctance to the idea of destroying the one person who mattered to him, but his years in the coven had affected him so deeply that he almost became a savage.
In 1905, Peter came back and told Jasper about the way vampires could coexist up North. He immediately left Maria and her coven to join Peter and Charlotte. However, he did not find peace, since he could still feel the emotions of his human victims, which deeply depressed him. Eventually, he left Charlotte and Peter. He tried to kill less often by hunting the sinister and would mostly steal blood bags from hospitals over the decades. However, his thirst always became overwhelming.
In 1948, he ran into a diner in Philadelphia and met Alice Cullen. At first, he was puzzled by her happy behavior around him, but nevertheless, her joyful emotions impacted him greatly. As it turned out, she had been waiting for him. When she held out her hand, he took it, and felt an unfamiliar emotion for the first time: hope.
He was able to learn from Alice's point how vampires had the ability to survive off of animal blood instead of human blood, as well as their future with Carlisle Cullen and his family. He didn't know such a thing could exist but he followed her. With the help of Alice's 'sight', they searched for the Cullens and eventually joined them in 1950. Sometime after that, by Carlisle's suggestion, he and Alice married. When he joined the Cullen family, Jasper changed his surname of Whitlock to his adoptive sister Rosalie's surname of "Hale" and poses as her twin due to their physical similarities. Out of the whole coven, Jasper has the hardest time being around humans, due to his unrestrained upbringing as a young vampire in a violent army environment. He was not taught to control or regulate his blood lust, and this imperfection continued throughout the next 50 years, leading him to burden himself with the mentality of feeling weak by not being able to possess the same level of restraint as the rest of his family.
Maria sought him out when they were in Calgary. The encounter prompted the family to move again, and Jasper politely asked Maria to keep her distance, because he had no interest in rejoining her coven and lifestyle. This upset Maria, which forced her to carry a grudge on Alice and the family for making him turn against her.
Throughout his time with the Cullens, he has attended high school and university many times, and earned degrees in history and philosophy.
Sometime in the 1980s, he started doing business with a lawyer who forged illegal documents to help provide his family with new identity certificates. After the lawyer retired, his apprentice, Jason Jenks, took over.