The Washington Post on Sunday published the first in a series of stories based on more than 11.9 million documents that expose a secretive financial universe that benefits the wealthy and powerful.

The vast trove of documents, known as the Pandora Papers, was obtained by the International Consortium of Investigative Journalists (ICIJ). The Post collaborated on the investigation, which involved more than 600 journalists in 117 countries and territories, the largest ever organized by the ICIJ.

The investigation exposes the offshore system that government leaders, billionaires and criminals often use to hide their assets. For an explanation of how offshore systems work and why people choose to hold their money in these companies, read our overview.

Within hours of publication, at least eight national governments promised to launch their own inquiries into the financial activities revealed in the papers.

Around the world, political players named in the investigation faced criticism for lavish spending and opaque practices.

Some defended their actions. Czech Prime Minister Andrej Babis, who is up for reelection this week, suggested Sunday that the Pandora Papers revelations about him are part of an effort to “influence the Czech election.”

Here’s what we know from our collective reporting

  • The files in the Pandora Papers detail the activities of nearly 29,000 offshore accounts.
  • Among them are more than 130 people listed as billionaires by Forbes magazine. U.S. states have become central to the global offshore system.
  • Leaders of countries on five continents use the offshore system, as well as 14 current heads of state or government.
  • Officials in Pakistan, Mexico, Spain, Brazil, Sri Lanka, Australia and Panama are set to launch inquiries in the wake of the Pandora Papers revelations.