Kevin North spent £50,000 on Vivienne Westwood clothing, a shopping trip to Harvey Nichols and propping up his failing pub business when he was given power of attorney by his elderly granddad.
By the time 84-year-old Norman Chipman died, his bank account was overdrawn and the planned family funeral had to be cancelled.
Sheffield Crown Court heard North, 31, was granted power of attorney in 2008 and was made trustee of his granddad’s estate, which included a £150,000 bungalow.
The court heard that in February 2010, Mr Chipman’s bungalow had been sold for £105,000 – yet 18 months later, there was nothing left.
Alexander Menary, prosecuting, said: “Norman Chipman eventually passed away in September 2011.
“By that time, he was insolvent and had no money left to pay for his funeral or carry out his wishes in relation to his ashes and those of his late wife.”
North had, rightly, spent some £40,000 on his grandfather’s care home bills, but at least £50,000 was spent on himself – including pumping money into his failing pub, the Good Companions on Haslemere Grove, Bentley.
Mr Menary said he had also been clothes shopping at Vivienne Westwood and went on a spending spree in Harvey Nichols.
In a victim statement read out in court, Mr Chipman’s son Paul, who had raised concerns about North, said: “In my father’s final years, I was denied access to my father due to barriers that had been created by Kevin.
“My father was a man of means, and was always responsible when it came to finances. He was never in debt to anyone.
“I suffered the shame and embarrassment of having to cancel the funeral my father deserved.
“It’s never been about money for my family and me, it’s about justice.”
Errol Ballantyne, for North, said: “The majority of the money was being used to keep himself afloat but he made sure his grandfather was well cared for and received what he needed at all times.
“He made sure he visited his grandfather and had become quite valuable in terms of moral support.
“He accepts he took advantage of that position. This wasn’t fraudulent from the outset but became so over a period of time.”
North, of Tennyson Avenue, Sprotbrough, pleaded guilty to one count of fraud.
Sentencing him to 40 months, the Hon Mrs Geraldine Justice Andrews told him: “The sad fact of life is by the time your grandfather passed away he was insolvent because you had depleted what was left of his money.
“That was possibly the most gross abuse of trust one can possibly describe.
“Your grandfather did not live to suffer the indignity of being penniless but it had come close to the wire.”