Franklin McLeod, 55, attacked Marlene Coleman in a fit of rage on June 17 last year at her home in Lewisham, southeast London.
After knifing the Eurostar worker, he went to dispose of the kitchen knife he used to brutally stab her.
He later walked into a police station and reported that he had found her in a pool of blood on the floor.
Police officers rushed to the scene and discovered the 53-year-old lying face down with a stab wound passing all the way through her neck.
Despite denying the charge of murder and insisting that he loved her, McLeod was convicted by an Old Bailey jury and was today and was jailed for life.
Jurors heard that the two had been in a relationship for more than ten years, in which Coleman had complained to friends that he was “jealous and possessive.”
Prosecutor Gareth Patterson KC had said: “She stated that when she challenged him about things he was sometimes violent towards her, however she would never go into detail.
”She had become unhappy in their relationship and had wanted it to end, however McLeod had refused to leave.”
In the years before her murder, Coleman had struck up a friendship with another man, Kevin Williams, who lived in Jamaica and was helping her build a house there.
Patterson said: “Things came to a head last year. She planned to fly on her own to Jamaica on June 21, 2021.
“A few days before her planned trip the defendant searched through Coleman’s phone. On it he found voice notes which had been sent to her by Kevin Williams. The defendant, in his anger, confronted Coleman about what he had found.”
An argument broke out in which McLeod used the knife to stab her to death before leaving the property to go for a walk, in which it is believed he disposed of the weapon.
After arriving at a police station, he told police that they had argued and he had put his hand around her throat and she fell unconscious.
He claimed that he went out to clear his head and upon his return, he found her in a pool of blood and blamed a “mystery attacker”.
McLeod told officers that they should be looking for someone else, although there was no evidence of an intruder.
In a victim impact statement by her sister Pamela Campbell, Coleman was described as “hardworking” as well as “self-sufficient and full of personality”.
Her sister continues to call her voicemail each day to hear her voice and spoke of the “intense pain” she feels about her sister’s last moments.
“You intended to kill her, I am quite sure from the evidence I have heard,” Judge Angela Rafferty KC said.
“You left her to die on the floor and she bled to death. In the aftermath you did nothing to help her or try to comfort her and you left the house and went for a walk, in which I am sure you disposed of the knife.”
She said that evidence showed that McLeod was “unreasonable, unhelpful and watchful over her, and she was seeking an escape”. She noted that the murder was significantly aggravated by the fact the knife had been targeted at her neck, that it had occurred in her home and that his first thought had been to dispose of the weapon rather than seek help.
He was jailed for life and must serve a minimum term of 20 years before being eligible for release.