It is alleged that Peter Stalgis "buried his head in the sand" when a mortgage scheme left the couple with a huge debt that he had kept from his partner Angela Conoby.
Stalgis was arrested at the property in Berkeley Mount, in the Harehills area of Leeds, on May 20 this year, just days before they were due to be evicted.
At the start of the murder trial in Leeds Crown Court today, jurors heard that a lone police officer had to force his way inside the house and found Stalgis sitting on a sofa in the dark, next to a nearly empty whisky bottle and with the television on.
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Footage from the officer's body camera was shown in the courtroom and Stalgis can be heard repeatedly saying "I lost the house", "she didn't know" and "I'm sorry".
There was a large kitchen knife near him on the floor and when the officer asked him where Ms Conoby was, he pointed and at the other side of the room the officer discovered Ms Conoby's lifeless body.
Stalgis pleaded not guilty to Ms Conoby's murder at an earlier hearing and prosecutor Jonathan Sharp said the defendant claimed he had no recollection of killing Ms Conoby, nor the reasons why, despite earlier confessions to police.
Addressing a jury of seven women and five men, Mr Sharp opened the trial, saying: "It's a tragic case.
"Peter Stalgis was in a loving relationship with his partner Angela Conoby for more than 30 years but their house was being repossessed and it seemed money worries overwhelmed them so he attacked her and stabbed her to death and as you will hear, there will be no dispute in this trial that that is what he did."
Members of the jury were told they only had to establish if Stalgis intended to cause her serious harm to find him guilty of murder.
Mr Sharp added: "From the nature of the injuries that he inflicted on his partner Angela Conoby, the Crown say you will be left in no doubt at the time he inflicted the injuries, he did intend to inflict at least serious harm to Angela."
The court heard that the couple had met while both worked for Burtons, where Ms Conoby was employed until 2017. An injury had since caused her mobility to be effected and she had been using a zimmer frame. Stalgis, meanwhile, had been working night shifts as a cleaner at the Neville Hill railway depot.
Stalgis had bought the house they shared in 1986 and when Ms Conoby moved in, in 1990, the pair remortgaged the property. In doing so they borrowed a sum of Â£21,900 and entered into an interest-only endowment mortgage.
Such an arrangement can lead to a dividend to pay off any borrowing and more, but when the policy matured it only offered a pay out of just under Â£10,500.
Mr Sharp said that by the early part of this year, Stalgis had got the pair into "severe financial difficulties or at least he thought he had".
Repeated attempts by the couple's building society and solicitors to contact them about the money they owed went unanswered, so too the subsequent eviction notices.
"For whatever reason, Mr Stalgis never tried to do anything about the situation," Mr Sharp said.
Even the building society's cheque for the sum generated at the end of their mortgage policy was never cashed in.
The couple were due to be evicted on May 23 this year but Mr Sharp said it was not known if Ms Conoby had even seen any of the solicitors' letters.
"Mr Stalgis made no contact with anyone, he answered none of the letters. He kept this to himself," Mr Sharp said.
The only time it seems he did try to make contact with the solicitors was via the phone on May 7 when the office was unmanned during the early May bank holiday. The following day Stalgis called in sick to work.
"We can't say exactly when it was that Mr Stalgis killed Angela Conoby but it is likely that it was around this time around the 7th or 8th of May, when for the first time we know not why he called the solicitors and called in sick to work," Mr Sharp said.
Ms Conoby was last seen alive on April 25 when she and Stalgis attended a family funeral and the last time she spoke to anyone is believed to have been on April 29 when she spoke on the telephone.
Following a lengthy subsequent silence, Ms Conoby's sister, Michaela, grew concerned and after being told not to visit by Stalgis and then receiving no response when she knocked on the door, she called the police.
After his arrest, at the police station Stalgis confided that he had "done a really bad thing" and asked for forgiveness "for killing the woman he loved", the court heard. Officers also discovered he had cuts to his left wrist that may have indicated a suicide attempt.
Later, when he was formally interviewed, he made no comment to the police's questions.
At the house, police found a pile of letters from solicitors and an apparent suicide note written by Stalgis which was addressed to Ms Conoby's sister and her partner. The letter was read out in court and said: "I lost the house and I killed the love of my life. I cannot live with the shame, please forgive me if you can. I deserve to rot in hell. As my friends and family I'm so, so sorry to put you all through this. I love you."
Mr Sharp said a pathologist and forensic scientists who examined Ms Conoby's body found that she had died after a "violent attack with a sharp implement, probably the knife that had been beside her on the floor". On the hilt of the knife, forensics found traces of Ms Conoby's blood.
Ms Conoby had suffered numerous knife wounds including a large wound in her neck, Mr Sharp said, adding: "She had quickly bled to death. She had died where she was found. Her body had not been moved.
"The nature of the injuries he inflicted on Angela.. make it clear to the Crown that he intended her to at the very least cause very serious harm."
Stalgis is charged with Ms Conoby's murder between April 28 and May 22 this year.
The trial continues.