Open this photo in gallery

       Cardinal Angelo Becciu talks to journalists during a news conference in Rome, on Sept. 25, 2020.

       Gregorio Borgia/The Associated Press

       A trial opened Tuesday within the Vatican City’s imposing walls of 10 defendants, including a once-powerful cardinal, in a case based on a sprawling probe into the allegedly criminal management of the Holy See’s portfolio of assets, including donations by countless Catholics from the pews.

       Among the defendants is an Italian prelate, Angelo Becciu, a long-time Vatican diplomat whom Pope Francis raised to cardinal’s rank in 2018. After a web of scandals started unravelling during a two-year investigation, Francis gave Becciu the boot last year as chief of the Catholic church’s saint-making office. Not waiting for find out the eventual verdict of a Vatican court, Francis also has removed Becciu’s rights as a cardinal.

       Less than three months ago, it would have been impossible for a cardinal to be in the dock in Vatican City State, which has its own justice system and even a jail. But Francis had a Vatican law changed so that Vatican-based cardinals and bishops can be prosecuted and judged by the Holy See’s lay criminal tribunal as long as the pontiff signs off on that. Previously, Vatican cardinals could only be judged by their peers, a court of three fellow cardinals.

       Becciu, 73, is charged with embezzlement and with pressing a monsignor to recant information he supplied to prosecutors about the handling of the disastrous Vatican real estate investment in London. Becciu has denied any wrongdoing.

       Since a nearly 500-page indictment was issued in early July, prosecutors have filed some 30,000 pages of supplemental documentation.

       Defense lawyers say they haven’t sufficient time to study the material.

       The presiding judge, Giuseppe Pignatone, is a retired chief prosecutor of Rome who earlier in his career took on the Mafia and economic wrongdoing in Sicily.

       To accommodate the largest criminal trial in the Vatican’s modern history, the hearings are being held in a large hall converted into a courtroom in the Vatican Museums.

       A pool of reporters accredited with the Vatican is being allowed to follow the proceedings in court, but their accounts aren’t allowed to be filed until after the day’s hearing ends.

       Defendants are alleged to have had various roles in actions that effectively cost the Holy See tens of millions of dollars in donated funds through poor investments, dealings with shady money managers and purported favours to friends and family.

       Story continues below advertisement

       Looming large in the indictment is the London deal approved by the Vatican secretariat of state. An initial €200-million (now nearly $240-million) was sunk into a fund operated by an Italian businessman. Half that money went into the real estate venture in the swank Chelsea neighbourhood, an investment which eventually cost €350-million. By 2018, the original investment was losing money, and the Vatican scrambled to find an exit strategy.

       Defendants include Cecilia Marogna, who was hired by Becciu as an external security consultant. Prosecutors allege she embezzled 575,000 euros in Vatican funds that Becciu had authorized for use as a ransom to free Catholic hostages abroad. Marogna has contended that charges she ran up were reimbursement of her intelligence-related expenses and other money was her compensation.

       Our Morning Update and Evening Update newsletters are written by Globe editors, giving you a concise summary of the day’s most important headlines. Sign up today.