A man has been jailed for 10 years for the manslaughter of his ex-girlfriend after she killed herself as a "direct result" of his controlling behaviour.
Nicholas Allen was jailed after what is thought to be the first manslaughter case brought in such circumstances.
Allen, 47, sent Justene Reece abusive voicemails, texts and Facebook messages and stalked her, the trial heard.
Ms Reece, who was 46, hanged herself in February and left a note saying "I've run out of fight."
Allen, who has a string of convictions for assault and harassment against other partners, was also convicted of "controlling and coercive behaviour" and of six counts of stalking Ms Reece and her family.
For these he was further sentenced to three years, to run concurrently.
On sentencing, Judge Michael Chambers QC said Allen had "clearly caused" Justene to commit suicide and made her life "a living nightmare".
"It is not suggested that you intended at any time that she should die but clearly you intended that she should suffer serious psychological harm.
"She committed suicide as a direct result of your sustained and determined criminal actions - actions which you clearly knew were having a profound effect upon her."
Senior Crown Prosecutor Hannah Sidaway said: "This was an exceptional case. Allen subjected Justene and those close to her to a sustained campaign of torment until she was unable to endure his behaviour any longer.
"There is no doubt he ultimately caused her to take her own life," she added.
The court heard that after Allen found out about Ms Reece's death he looked online to see whether he could be held legally responsible.
Ms Reece and Allen had known each other since they were teenagers because of their shared interest in scooters. They began a relationship in the summer of 2015 and later that year moved in together in Stafford.
But the pair separated in October 2016 partly because of domestic abuse perpetrated by Allen, the court heard.
Ms Reece told police Allen had become "very manipulative, controlling and cold".
He had fitted a tracer to her scooter, was sending her hundreds of texts and messages when she went out, tracking her on social media and sometimes stopping her from going out.
Prosecuting, Andrew Smith QC said: "When Ms Reece tried to leave the house Mr Allen would physically throw her to the floor.
"On two separate occasions he put his hands around her neck and physically stopped her from leaving the house," he said.
By Danny Shaw, BBC home affairs correspondent
Earlier this month, an inspection report found that harassment and stalking victims were being let down at every stage of the criminal justice system in England and Wales.
But the bold decision to charge Nicholas Allen with manslaughter demonstrates an awareness of the devastating impact of such behaviour - and it may signify a step-change in the way the authorities deal with it.
From a legal point of view, the case is extremely unusual. People convicted of manslaughter have usually physically caused the death, for example, pushing someone, who then falls and suffers a fatal head injury.
It raises the prospect of other prosecutions, in cases where someone has taken their own life as a result of someone else's criminal actions.
Ms Reece left Allen and moved into a women's refuge in another part of the country. But, the court heard, he became "obsessed" with finding her and tried to contact her 3,473 times in five and a half months.
She obtained a non-molestation order, an injunction to prevent Allen from threatening or harming her, but he breached it within three days by trying to contact her through social media.
"With increasing frequency, Mr Allen continued to adopt false identities, in a variety of forms, in his stalking of Ms Reece and those closest to her," said Mr Smith.
In November 2016, Ms Reece moved back to Stafford. At this point, she was taking medication for depression and rarely left her house. Allen got back in contact with her and told her he loved her, saying he was tracking her movements.
Police warned Allen "to cease all contact" but he ignored them and tried to contact her with "real intensity" over Christmas.
In January, Ms Reece found a near-identical Facebook profile to her own had been set up saying she had been raped some years earlier. Another fake account, also under her name, claimed she had blamed two innocent men for it.
Later that month Ms Reece took an overdose in an attempt to take her own life.
"Medical records make clear that her taking of the overdose was directly linked to Mr Allen's actions in relation to both herself and her friends and family," said Mr Smith.
In February, Allen was arrested for harassment. Ms Reece told police he was intimidating and harassing her "to the point where I cannot now sleep".
She added: "I am doing everything I can to keep myself and my friends and family safe but Allen just will not leave us alone."
'Living in fear'
Friends said she had gone from being a confident, "bubbly" woman to a "skeleton" who could not function.
On 22 February, Ms Reece's body was found in the kitchen of her home.
A consultant psychiatrist who reviewed all the evidence and medical records said she had been in a "substantially abnormal" mental state, suffering from depression, panic attacks and feelings of hopelessness.
Mr Smith told the court the doctor had concluded there was a "clear link between Ms Reece's mental state caused by the actions of the defendant and her taking her own life".
Ms Sidaway said: "This case illustrates the devastating effect that stalking can have on victims. It reaches into every aspect of their lives, causing acute distress and leaving them, and often their families, living in fear."
In a statement released by Staffordshire Police, Ms Reece's family said Allen's actions caused "a dramatic transformation in Justene's personality and health".
"She changed from a very bubbly and loving person to someone who was timid, afraid, lethargic, and frightened to leave the house. This was shocking to us all. We take some small comfort in the fact Nick Allen has now been convicted and sentenced for his actions."