The greatest mathematical discovery?

Introduction

Question: What mathematical discovery more than 1500 years ago:

Is one of the greatest, if not the greatest, single discovery in the field of mathematics?
Involved three subtle ideas that evaded the greatest minds of antiquity, even including geniuses such as Archimedes?
Was fiercely resisted in Europe for hundreds of years after its discovery?
Even today, . . . → Read More: The greatest mathematical discovery?