His greatest reforms were, however, economic and financial, with the creation of several companies and guilds to regulate every commercial activity. He created the Douro Wine Company which demarcated the Douro wine region for production of Port, to ensure the wine's quality; his was the second attempt to control wine quality and production in Europe, after the Tokaj region of Hungary. He ruled with a heavy hand, imposing strict laws upon all classes of Portuguese society, from the high nobility to the poorest working class, and via his widespread review of the country's tax system. These reforms gained him enemies in the upper classes, especially among the high nobility, who despised him as a social upstart.
