Ashley Williams deprived his children of their mother after carrying out a "cruel and violent act", police have said, as the 49-year-old was jailed for life.
The 49-year-old was ordered to spend at least 25 years behind bars after setting Julie Beattie on fire in July last year.
Detective Inspector Sharon Marman, Homicide and Major Crime Command, said:
Julie Beattie suffered a horrific death at the hands of Williams which was an extraordinarily cruel and violent act.
Through his actions Williams has deprived his children of their mother and he will have to live with this for the rest of his life.
Read: Williams killed partner after learning she was about to leave him
A man convicted of murdering his young partner set her on fire after learning that she was about to leave him.
Ashley Williams, who has been ordered to serve a minimum of 25 years in prison, became suspicious that Julie Beattie was having an affair in the weeks before her address.
Ms Beattie had made plans to leave Williams, who she had been with since she was 16-year-olds, and recently had been given a council property in another area.
After discovering that his partner was collecting belongings from the property, Williams returned and prevented her from leaving.
He then attacked the 24-year-old with a hammer before setting her on fire.
A man who killed his partner by setting her alight after learning that she was about to leave him has been jailed for life.
Ashley Williams, 49, used a hammer to attack Julie Beattie, 24, the mother of his four children, before covering her in fuel in their kitchen in Asolando Drive, Walworth in July 2013.
Ms Beattie staggered outside after the incident and managed to tell a neighbour that "Ashley did this to me".
Williams was ordered to serve a minimum of 25 years in prison before being considered for release.