It started in the late 17th Century. King William III (of William and Mary fame) needed funds to fight the French. He put together a syndicate of City merchants and asked them to raise money for him. This syndicate later went on to become the Bank of England. Thus started the UK's national debt.
The debt grew during the 18th Century but then fell continuously during the 19th Century. But in the 20th C it grew to fund the First World War, then it grew more to fund the Second World War and post-War governments were profligate and it grew more. By the time John Major left office in 1997 the debt stood at about £400bn.
And today it has just passed one trillion pounds. Check out the debt clock on the right hand side.
New Labour, during their decade of misrule, more than doubled our national debt. Last year every household in the UK paid £1200 in interest payments alone. The scale of New Labour's incompetence has been staggering.
But it's going to get higher; much higher. There are plans to include in the official number the cost of bailing out the banks. Expect another trillion or more to be added before too long.