In the books we read about marvelousmarvellous feats of dark magic done by poweful dark wizardspowerful Dark Wizards other than Voldemort - like the deeds of Herpo the Foul, who created Horcruxes, or Salazar Slytherin, who made the Chamber of Secrets.
So, we know there were some other dark wizardsDark Wizards of great power.
Is there any evidence that they tried to conquer the world?
If not, why wouldn't they try? Or why would these triesattempts be concealed?