Four former Volkswagen executives received prison sentences Monday for their role in the emissions-cheating scandal that fundamentally transformed Europe’s car market. The verdict, delivered after a three-year trial in Braunschweig, Germany, marked the latest chapter in a 10-year-long saga that reshaped the continent’s relationship with diesel technology.

Jens Hadler, who oversaw diesel engine development, received the harshest sentence of four and a half years for orchestrating what judges called “particularly serious” fraud. His team had installed software allowing vehicles to recognize emissions testing, temporarily increasing pollution controls during inspections while running dirty the rest of the time.

The scandal’s impact extended far beyond corporate boardrooms. Before 2015, diesel vehicles commanded over half of Europe’s car market, marketed as environmentally friendly alternatives to gasoline. Today, that figure has collapsed to just 10% of new car sales.

The whole affair also accelerated Europe’s transition toward electrification. Electric vehicles and plug-in hybrids now account for 25% of new car sales, while Volkswagen itself has become Europe’s leading EV manufacturer, selling three times as many battery-powered cars as Tesla in April, reports The New York Times.