Former News of the World editors Rebekah Brooks and Andy Coulson must have known about phone hacking at their newspaper, the Old Bailey has heard.
Andrew Edis QC said the prosecution would be able to show there had been phone hacking at the now-closed paper.
Mrs Brooks and Mr Coulson - among eight on trial - deny charges including conspiracy to intercept communications.
The court heard that three other News of the World journalists had already admitted conspiring to hack phones.
Mr Edis said they were Greg Miskiw, Neville Thurlbeck and James Weatherup, who are not on trial.
He said private investigator Glenn Mulcaire had pleaded guilty earlier this year to three counts of conspiracy to hack phones in relation to murdered Surrey schoolgirl Milly Dowler and others.
Mrs Brooks is also accused of approving payments to public officials while she was editor of the Sun after 2003.
She allegedly approved nearly £40,000 of payments for stories from a security-cleared MoD official.
Mr Edis, opening the prosecution case on Wednesday, said: "We say we will be able to show that there was phone hacking at the News of the World. That Glenn Mulcaire did it. That Clive Goodman did it. And that Ian Edmonson did it.
"Were they asked as part of the conspiracy, given that they were so senior at the paper? They wanted it to happen because they were in charge of the purse-strings... so you may say that if they didn't stop it, they were part of the conspiracy to carry on."
He told the jury it was "quite a simple issue": "There was phone hacking - who knew?"
Mr Edis said "there was phone hacking during both periods" when Mrs Brooks and Mr Coulson edited the News of the World.
"You will have to decide whether it could happen without the editor knowing," he told the jury.
He later said: "The News of the World is a Sunday paper. That means it published once a week, 52 times a year. It wasn't War And Peace. It wasn't an enormous document.
"It was the sort of document that if you were its editor you could actually take an interest in its content without too much trouble.
"What you are going to have to consider is whether these people were doing their jobs properly, in which case we say they must have known what they were spending the money on.
"They must have known, we say, where these stories came from, otherwise they would never have got into the paper."
Mr Edis told the jury there would be timelines relating to famous people including Sir Paul McCartney, Jude Law, Lord Prescott and others.
Mr Edis said one of the defendants, Mr Edmonson, had commissioned Mr Mulcaire to carry out "an undoubtedly large number of phone hacks".
One hack related to someone who knew actress Joanna Lumley, and police had found recordings of 13 of Lord Frederick Windsor's voicemails.
There were also recordings of voicemails left by former Home Secretary David Blunkett, the court was told.
Mr Edis told the jury the prosecution would show Mr Edmondson had hacked the phones of journalists at rival papers, including the Mail on Sunday.
Earlier in his opening speech, Mr Edis told the jury of nine women and three men that the News of the World had closed because it had been discovered that someone at the newspaper had hacked the phone of a "young murdered girl, Milly Dowler."
He said that phone hacking meant listening to other people's voicemails without their consent, usually by finding the passcode needed to listen to messages left for them by someone else.
Mr Edis said the newspaper had employed Mr Mulcaire to be involved in phone hacking in order to find or develop stories that would eventually make it into the News of the World's pages.
He said public officials, including prison officers and soldiers, sold information to the News of the World and the Sun, and that was a crime.
The third set of allegations faced by some of the defendants concerned hiding possible evidence - perverting the course of justice, he said.
Mr Edis said Mrs Brooks, Mr Coulson and colleagues Mr Edmondson and Stuart Kuttner were charged with conspiracy to intercept communications by listening to voicemails.
Mr Coulson and reporter Mr Goodman are alleged to have paid a Buckingham Palace police officer for a copy of the royal household telephone book.
Mr Goodman allegedly asked Mr Coulson to approve a payment to a palace police officer.
Further charges allege an attempt to cover-up evidence involving Mrs Brooks, her PA Cheryl Carter, husband Charlie Brooks and security chief Mark Hanna.
Mr Edis said Mr Mulcaire pleaded guilty to conspiracy to hack phones in November 2006 and was sentenced for that along with Mr Goodman.
The trial, which could last up to six months, was adjourned until Thursday when Mr Edis will continue his opening. All the defendants deny the charges they face.