The European Union’s highest court on Tuesday delivered a major victory in the bloc’s yearslong campaign to regulate the technology industry, ruling against Apple and Google in two landmark legal cases.

The decisions, issued by the Court of Justice of the European Union, were seen as an important test of efforts in Europe to clamp down on the world’s largest technology companies. Apple and Google have been frequent targets for E.U. regulators, and the companies have battled the cases for years.

In the Apple case, the court sided with a European Union order from 2016 for Ireland to collect 13 billion euros, worth about $14.4 billion today, in unpaid taxes from the company. Regulators determined that Apple had struck illegal deals with the Irish government that allowed the company to pay virtually nothing in taxes on its European business in some years.

Apple won an earlier decision to strike down the order, a ruling that the European Commission, the E.U.’s executive branch, appealed to the Court of Justice. As the case winded its way through the appeals process, the €13 billion was placed in an escrow account until a final judgment. The money will now be released to Ireland, a sizable injection to the country’s treasury.

Apple said the decision effectively allowed the European Union to impose a double tax on company income that is already taxed in the United States.

“This case has never been about how much tax we pay, but which government we are required to pay it to,” Apple said in a statement on Tuesday. “The European Commission is trying to retroactively change the rules and ignore that, as required by international tax law, our income was already subject to taxes in the U.S.”