A News International "private wire" phone line attempted to hack the voicemails of former News of the World deputy editor Neil Wallis, the hacking trial has heard.
In addition, the same phone system attempted to access the voicemails of two senior royal aides hundreds of times in less than a year.
The mobile phones of the right-hand men to the Prince of Wales, the Duke of Cambridge and Prince Harry were targeted by the line hundreds of times between 26 October, 2005 and 5 August , 2006, the Old Bailey heard.
The private wire, which allowed desk-based landlines to route calls through a mobile number, tried to access the voicemail of Jamie Lowther-Pinkerton, private secretary to William and Harry, 416 times and attempted to hack the phone of Mark Dyer, former private secretary to Charles, 296 times, it was alleged.
Both men have close personal ties to the royal family.
Lowther-Pinkerton, who stood aside from his full time roll as private secretary last year but still works with William, Harry and the Duchess of Cambridge, is so close to the family that he was appointed godfather to Prince George earlier this year.
And Dyer, former equerry of Charles, was appointed as the Prince of Wales' private secretary with responsibility for William and Harry in the eight years following the death of their mother Diana, Princess of Wales.
The private wire also tried to intercept the phone messages of former culture secretary Tessa Jowell, former glamour model Katie Price, rival journalists at the Mail on Sunday and former News of the World deputy editor Neil Wallis, the trial of several former News International employees has heard.
Jurors were shown a document detailing the alleged hacking attempts. The log showed 850 calls from the private wire to the phone numbers or voicemails.
Earlier in the day jurors were given an insight into the workings of private investigator Glenn Mulcaire.
They were shown whiteboards and notes taken from Mulcaire's home and business premises when he was arrested in 2006.
Presenting the whiteboards to the court, Detective Sergeant James Guest described how one had the "Vodaphone password of the week" on it.
Another showed a spider diagram which had the word "services" in the middle with a line linked to the words "Charles Rae meeting" and then "Rebekah Wade" – the maiden name of Rebekah Brooks.
Another board had "project targets" written at the top with a list underneath including: Buncefield investigation, footballers David Ginola and Tony Adams and the words Bulger inquiry.
The jury has already been told that Mulcaire has admitted phone hacking.
Today they were also given a lesson in hacking phones by Operation Weeting officer Detective Constable Richard Fitzgerald.
Former News International chief executive Rebekah Brooks, 45, of Churchill, Oxfordshire; ex News of the World editor Andy Coulson, also 45, from Charing in Kent; former NoW head of news Ian Edmondson, 44, from Raynes Park, south west London; and the tabloid's ex-managing editor Stuart Kuttner, 73, from Woodford Green, Essex, are all on trial accused of conspiring with others to hack phones between 3 October 2000 and 9 August 2006.
Former NoW and Sun editor Brooks is also accused of two counts of conspiring with others to commit misconduct in public office – one between 1 January 2004 and 31 January 2012 and the other between 9 February 2006 and 16 October 2008 – linked to alleged inappropriate payments to public officials.
She faces another two allegations of conspiracy to pervert the course of justice – one with her former personal assistant Cheryl Carter, 49, from Chelmsford in Essex, between 6 July and 9 July 2011; and a second with her husband, Charles Brooks, and former head of security at News International, Mark Hanna, and others between 15 July and 19 July 2011.
Coulson is also facing two allegations that he conspired with former NoW royal editor Clive Goodman, 56, from Addlestone in Surrey, and other unknown people to commit misconduct in public office – between 31 August 2002 and 31 January 2003, and between 31 January and 3 June 2005.
All of the accused deny all of the charges.
The trial has been adjourned until Wednesday.