ronib
It’s the concept of debt being carried forward into the future which started with the aftermath of the Napoleonic war and obviously not the amount of debt incurred 400 years ago … of course that particular debt has gone. It’s only fairly recently that the debt from the 2nd World War has been repaid. Clearly the costs of the pandemic will be paid for in the years to come.
The 'cost' of the pandemic was raised by Quantitative Easing. That is when the Bank of England buys bonds, usually bonds newly issued by the Treasury, with money it has created and the money the Treasury receives is either spent by the government, or, in the case of the 2008 QE, is used to enlarge the commercial banks' reserve accounts, the accounts through which all interbank transactions are conducted. The reserves are very big now because the government promised to guarantee all bank deposits (i.e. customers' bank accounts) up to a maximum of £85,000 in the case of bank failure.
As the QE money was 'created' by the BoE it isn't owed to anyone. Technically the Treasury owes it to the BoE but as the BoE is owned by the state and the state can't owe itself money, it isn't going to be paid back at any time.
Some £900billion of QE has been created since 2008. It is counted in the government's borrowing figures, which makes the 'debt' look excessive, but it is a fictional loan, nothing to worry about. The rest of the government's 'debt' is money from the sale of bonds and National Savings accounts. These are savings and investments (notably investment by pension funds. People have been buying government bonds to provide an investment income for centuries.
They don't usually want their money back unless they are short of money, or, like the pension funds after the Truss/Kwarteng budget, which needed money to cover their financial commitments because the fall in sterling had caused some of their other, more risky investments to fall in value.
If the £900billion were to be taken off the 'debt' figure, the 'black hole' wouldn't look nearly as black...
As Dinahmo said, government debt didn't start with the Napoleopnic Wars, it had been in existence before that because that's how the country financed its wars...And we've had a good many wars to finance over the centuries...
Interestingly, in WW1, the government war bonds weren't selling very well so the BoE instructed one of their staff to buy a large quantity and put the money into his account for him to buy them with! An early instance of QE, I think. 



