Void Century

The Void Century is a century-long gap in recorded and archaeological history, the study of which is forbidden by the World Government. These events occurred 800 to 900 years before the current storyline. It was hinted at during the Skypiea arc; the dates were seen in Robin's flashback. This period became known as the Void Century because there is nothing left to acknowledge anything that happened in it, aside from the poneglyphs which are written in a language that few know how to read.

However, it causes a problem with the known histories of the world as nothing ties up because of that missing period. Though many seem to know there is a gap in the historical record, virtually everyone is unaware that filling in this gap is possible. For example, Nefertari Cobra, after being told by Nico Robin about this missing period, was completely shocked that a way to "tie the threads of history together" existed. The fact that filling the gap is possible was proven when "Dark King" Silvers Rayleigh revealed that the Roger Pirates discovered the true history. 800 years ago, at the end of the Void Century, the World Government was born and took political control of the entire world, uniting all countries and forming the Council of Kings. For the World Government, the events of the Void Century were better left unknown as information linked to it is considered far too dangerous. When the research of the Poneglyphs was outlawed, hundreds of scholars across the world were killed. Since then, a ban on any research related to the Void Century has been put in place. At the end of the Void Century, the 20 kingdoms came together to defeat the Ancient Kingdom and then founded what is now known as the World Government. The exact process of how it was founded and how they covered up the 100 year gap remains unknown.