A Bristol Crown Court jury found David Main guilty by an 11-1 majority verdict of murdering Joan Main, his first wife and a mother of three, in January 1973. The body lay undiscovered for 20 years.
The jury had heard that the financially-pressed plumber strangled his 35-year-old ex-wife before cramming her body into an oil drum and sealing it with concrete.
The 45-gallon drum was then placed under the concrete garage floor in his rear garden at Goddard Avenue, Swindon, Wiltshire.
Passing sentence, Mr Justice Ian Kennedy told him: 'You must be a man of utter cruelty that you could contemplate living in that house with your wife bundled into a barrel in the garden.'
Main shook his head repeatedly as he was led from the dock.
He had exercised his right to silence during the seven-day trial, giving no evidence and calling no defence witnesses.
His counsel, Michael Hubbard QC, maintained that Main had repeatedly denied the murder.
He argued that Main's financial problems were not sufficient for a murder motive.
Nigel Pascoe QC, for the prosecution, said Main, now 61, had killed Joan within days of her moving to a nearby house, which he had renovated as part of their divorce settlement.
They had divorced months earlier after 14 years of marriage. Main kept the truth from his children and in-laws.
As part of the deception, Joan's mother Rose King received a birthday card posted from Wales. Inside was a pounds 1 note and the message: 'To Mum, love Joan.'
Experts maintained the handwriting was Main's, said Mr Pascoe.
Main married his second wife Madeleine in 1972, but it ended in divorce 12 years later. She committed suicide in 1989.
Main was arrested on 1 March last year and police recovered the oil drum after digging below concrete in the rear garden.
Detective Chief Inspector David Sinclair extended the force's sympathy to Mrs King, now 81, saying: 'She can put to rest 20 years of not knowing where her daughter was.'
Wiltshire police revealed they stepped up their investigation into Joan Main's disappearance after receiving new information early last year.Reuse content