A man threatened to kill his partner's family if she continued to try to end their relationship, a court heard.
Aaron Roberts, 40, had been in a formal relationship with the woman for around a year, though Preston Crown Court said they had known each other for around a decade.
Lisa Worsley, prosecuting, described how Roberts' controlling behaviour throughout the relationship left the victim feeling depressed.
She said the victim felt like Roberts "forced himself into my house and my life and wouldn't leave."
"She described how she felt she couldn't go out and became depressed and isolated from friends and family," Ms Worsley said.
It was heard how if the victim would try to go to her mother's house after dropping her children off at school, Roberts would chase her and scream at her.
Ms Worsley also described how the victim's children were "terrified" of Roberts, though he claimed the little boy needed "toughening up."
She said: "Roberts was aware she wanted to end the relationship, but he said if she didn't stop trying to leave he would kill her family to teach her a lesson."
As a result of Roberts' behaviour, the victim gave up her job at a hospital and after dropping her children at school she would stay at home as she was not able to go out.
On occasions, Roberts would pat her down and accuse her of having a second phone in order to cheat on him, and he would check her underwear to make sure she had not had sex with other people.
Roberts was arrested on September 22 and interviewed, where he denied the offences.
Shortly after the termination of the interview, described as less than half an hour, he twice called the victim asking her what she had told the police.
Roberts, of Burnley Road, Colne, pleaded guilty to counts of controlling/coercive behaviour and witness intimidation.
Emma Kehoe, in mitigation, said Roberts was "not proud of the way he has behaved."
She added that he self-medicates through drugs but has recognised "enough is enough" and he needs to "take the help that is offered."
Judge Richard Gioserano, sentencing, said: "You have been subject on a variety of occasions to restraining orders, bail conditions, and licence conditions.
"It's the opinion of the pre-sentence report author that you simply will not abide by the conditions imposed on you.
"You seem to pick and choose when you want to comply and when it doesn't suit you, you simply do not.
"It does seem the signs are positive, that you are preparing for a more productive release this time. Time will tell.
"But I've got no confidence at the moment you will comply with a suspended sentence order or a community order."
The judge sentenced Roberts to 18 months in prison and imposed a five-year restraining order between him and the victim.
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