Lord Black has been accused of stealing $60m (£31m) from Hollinger International while he was chief executive of the newspaper publisher.
Lord Black denies all the charges
The allegations were levelled against Lord Black, 62, and three other former executives on the first day of their trial for fraud and racketeering.
Lord Black is accused of skimming the money to fund a lavish lifestyle at the expense of Hollinger shareholders.
The Canadian-born British peer has vehemently denied the allegations.
Prosecutor Jeffrey Cramer opened the case by stating that the jury was "sitting in a room with four men who stole $60m, four men who believed their five- and six-figure salaries were not enough".
"It was theft, it was fraud, it was crime," Mr Cramer said.
15 charges of fraud
one of obstruction of justice
one of racketeering
Federal prosecutors allege Lord Black:
fraudulently received non-compete fees from the sale of Hollinger International assets
deprived the company of his honest services
repeatedly benefited himself at the expense of the company and its public shareholders through the abuse of company perks
Other executives on trial
John Boultbee - former chief financial officer
Peter Atkinson - former general counsel
Mark Kipnis - former corporate counsel and secretary
Countering the claims of the prosecution, Lord Black's lawyer Edward Genson said his client was "not guilty of each and every charge in this indictment".
Rather than stealing for himself, the company was, in fact, stolen from Lord Black, the lawyer argued.
The trial of Lord Black had been due to start in Chicago on Monday, but was delayed after objections from the media tycoon's lawyers about whether or not the former press baron would receive a fair trial.
Lord Black faces charges of fraud, racketeering, money laundering and obstruction of justice, and the trial could take up to four months.
If he is found guilty Lord Black may receive prison sentences totalling more than 100 years, as well as millions of dollars in fines and seized assets.
The lawyer leading the prosecution is Patrick Fitzgerald, who recently prosecuted Lewis "Scooter" Libby, former chief of staff to Vice-President Dick Cheney, for perjury.
Lord Black's co-defendants are:
- Jack Boultbee, 63, the former chief financial officer of Hollinger Inc, the firm which controlled and managed Hollinger International
- Peter Atkinson, 59, general counsel for Hollinger Inc
- Mark Kipnis, 60, corporate counsel for Hollinger International
Lord Black ran Hollinger International for eight years before stepping down in November 2003.
The company was the world's third-biggest newspaper publisher, and controlled titles including the UK's Daily Telegraph, the Jerusalem Post and the Chicago Sun-Times.
He is now facing accusations that he used company funds to pay for a lavish birthday party for his wife, journalist Barbara Amiel, as well as designer handbags, opera tickets and the refurbishment of a Rolls-Royce.
Among the other charges are that he sold company assets to himself at favourable rates - among them an apartment in New York.
Lord Black has been vocal in his condemnation of what he calls unfounded and unjustified accusations.
Last week, in an article called "I am not afraid", Lord Black said he was confident that he would be acquitted.