Robin Dupont, 57, attacked her while she was in bed at their home in the island in February last year.
He had spent several months suffering from a recurrent depressive disorder and he said that on the night he responded to voices in his head insisting he kill his wife and then himself.
He stabbed her in the upper body with two kitchen knives.
She woke up during the attack and later told police she thought she was having a nightmare. She described Dupont as seeming detached. She fell out of bed and he stopped the attack and left the house.
She was taken to the island’s hospital and treated for seven stab wounds to her shoulders and chest, one of which was 50mm deep, and two to her neck. She also received lacerations to her hands, consistent with trying to defend herself.
Dupont went to Braye Harbour, intending to drown himself, but changed his mind when in the water, drove to the hospital, and confessed to police.
A psychiatric report prepared for his defence found that Dupont was insane on the night, but this was reversed in a further report after the prosecution rejected that finding. A third report, requested by both sides, supported the findings of the second report.
In Guernsey’s Royal Court Dupont admitted a charge of attempted murder.
Prosecuting advocate Rory Calderwood said that as Dupont had brooded about the attack on the night, it was premeditated.
But defence Advocate Claire Tee said that the attack was shambolic, not premeditated and was unsophisticated. It was half-hearted, fleeting and wholly out of character.
Prior to this, there had been no violence between the couple.
Dupont had a number of supportive references submitted to the court, and his advocate argued that nothing other than an exceptionally lenient sentence was merited on account of what she called the truly exceptional circumstances of this case.
But in delivering the sentence, Judge Russell Finch said that Dupont had been well enough to be aware that the attack was morally and legally wrong.
The probation report said that a lot of work would be needed over a long period to address Dupont’s mental health issues.
‘It was only through luck or providence that you are not facing a murder charges,’ Judge Finch said. ‘Exceptional leniency is not called for. The intention was to kill.’
Dupont’s 12-year sentence was backdated to 19 February 2020, when he was taken into custody.
After his release, Dupont will be subject to an extended sentence of five years, meaning that he offends in that time he is liable to have to serve that sentence.