The Void Century is the greatest-known event in the world of One Piece and also the most mysterious one. As the name suggests, this is a period of a hundred years that spanned from 900-800 years ago in the One Piece world. The events that took place during the Void Century defined the current age that the people are living in.
However, surprisingly, not much is known about the events of this century as every major incident was eventually covered up by the World Government somehow. Yet, those inte rested in history have, over the years, uncovered the many secrets of the Void Century and now fans know quite a bit about the events that unfolded in this era.
7 The Great War
Undoubtedly, the most important event that took place during the Void Century was the Great War that defined the entire age. This war was fought between none other than the Ancient Kingdom and a collaboration of 20 nations that had banded together to take them down.
Why exactly they were opposed to the Ancient Kingdom isn't known just yet, however, it could very well be due to their vast scientific knowledge and technologically advanced society. This great war went on for quite a long time and ended with the defeat of the people of the Ancient Kingdom. In the future, fans will find out more about its events.
6 Construction Of Pluton On Water 7
Another major event that defined the era was the creation of one of the Three Ancient Weapons, the Pluton, during the Void Century. It is believed that the people of the Ancient Kingdom possessed extremely advanced knowledge and, as such, could easily craft weapons capable of mass destruction.
Pluton, which is known to have been a giant warship, was crafted by them on the island of Water 7 during this time. This is likely to combat the threat of the 20 Kings that had banded together. It is unknown if the people of the Ancient Kingdom actually did use the Pluton or not, however, it certainly came to life in this era and was eventually put to sleep under the land of Wano, once it got submerged.
5 Construction Of The Iron Giant
Recently, One Egghead Island arc introduced fans to an Iron Giant the remains of which lay on the island of Egghead at the moment. It is believed that this Iron Giant is powered by ancient fuel which Vegapunk believes to be a very unique power source.
This Ancient Giant was created by the people of the Ancient Kingdom over 800 years ago during the Void Century. 200 years before the current events, the Iron Giant launched an attack on the Holy Land of Mariejois with its ferocious power. Somehow, it was subdued and found its way to Egghead, where Vegapunk studied it, most likely.
4 Joy Boy's Promise
Joy Boy is known to have been the most prominent figure from the Void Century. It is believed that he had ties to the Ancient Kingdom and most likely held a position of great authority within it. Joy Boy had the power of the Nika fruit or was, perhaps, Nika himself. At some point, he got involved in the war against the 20 Kings.
Joy Boy was an incredibly kind soul and this is evident from the fact that he promised the Mermaid Princess, Poseidon, of Fish-Man Island that he would take them to the surface. Soon after, the Noah was crafted for this purpose. Unfortunately, Joy Boy wasn't able to accomplish this task, however, his will has been passed down and Luffy is the one who will accomplish this task for him.
3 Destruction Of Shandora
Shandora, also known as the City of Gold, existed during the Void Century and was one of the most prosperous places of the time. As evident from its name, the city was made entirely out of gold and held great significance in the One Piece world. Evidently, Shandora was a part of the Ancient Kingdom that was engulfed in the war against the 20 Kings.
Towards the very end of the Void Century, Shandora was eventually laid to ruin and that's what Robin discovers in the Skypiea arc of the story once she finds herself locating the ancient ruins. While Shandora itself was destroyed, the people who inhabited the place are alive and well on Upper Yard on Skypiea.
2 Creation Of The Poneglyphs
As the Ancient Kingdom started to lose the war against the 20 Kings during the Void Century, it became clear that their history would eventually be snuffed out by the victors.
To counter that and preserve both their will and their history, the members of the Kozuki clan, who were also potentially a part of the Ancient Kingdom at the time, crafted the Poneglyphs, which are known to be indestructible blocks of stone with bits of history engraved on them. Through this, their history was forever preserved.
1 Creation Of The World Government
Finally, once the war against the Ancient Kingdom came to an end, the rise of the World Government came to be. The 20 Kings that had banded together to combat the Ancient Kingdom became the rulers of the war and established the World Government. These 20 Kings then lived in the Holy Land of Mariejois, atop the Red Line.
They swore a vow that nobody would be above the other in front of the Empty Throne, however, little did they know that the world already had an emperor, Imu. The descendants of the 20 Kings came to be known as the Celestial Dragons and they hold tremendous power in the One Piece world today.