A gang hatched a plot to con the Bank of England out of £28bn by producing fake bank notes, a court has heard.
But the "audacious" plan involved £1,000 notes which had not been legal tender for more than 60 years, Southwark Crown Court was told.
Prosecutors Martin Evans said if the fake bank notes had been genuine they would have been worth almost 75% of the £39bn currently in use worldwide.
All six defendants deny conspiring to defraud the Bank of England.
The charges relate to a period between 1 December 2006 and 27 March 27 2007.
Denying the charge is Ross Cowie, 62, of Fairholme Road, West Kensington, west London, who described himself as an Australian lawyer, and the family's so called "chief" Chin "Daniel" Lim, 50, of Prince's Plain, Bromley, south London.
Also before the court are Kim Teo, 41, of Lichfield Grove, Finchley, north London, said to be a solicitor; Ping Mak, 56, and Kwok Chan, 55, both of Colson Way, Streatham, south-west London and Chi Chung, 53, of Frithville Gardens, Shepherds Bush, west London.
At the opening of the trial jurors heard that the plan was further undermined by the use of "special issue" notes, with a face value of £500,000, which had never existed.
Bank officials were told the notes were real and owned by a so-called "family" of former Chinese nationalist officials, the oldest one of whom was 116.
Mr Evans explained that the signature, apparently forged on the samples recovered, was incorrect.
He said Sir Jasper Quintus Hollamalways, appointed chief cashier of the Bank of England in 1963, used his first two initials when signing his name, whereas the alleged counterfeiters had only used the second.
Mr Evans said the case was "an audacious plan to present counterfeits, pieces of paper that resembled bank notes, in order to persuade the Bank of England to honour the promise all bank notes carry".
The bank was first approached through an e-mail from Mr Cowie who said he had a number of £1,000 bank notes he wished to redeem for a more current currency.
After revealing he also had £500,000 notes to exchange, bank officials became suspicious and alerted the police.
The case continues.