The Void Century is a mysterious and highly significant period in the world’s history, spanning 100 years. It occurred approximately 900 to 800 years before the current storyline and is notable for being completely erased from historical records by the World Government.
During the Void Century, there existed a powerful civilization known as the Ancient Kingdom. This kingdom is believed to have been an advanced and thriving society, with a philosophy and way of life that were at odds with the Twenty Kingdoms, which later formed the World Government. The Ancient Kingdom is often linked to the mysterious "D" lineage and is thought to have been a major force in the world.
The end of the Void Century saw the fall of the Ancient Kingdom and the rise of the Twenty Kingdoms, which allied together to defeat the Ancient Kingdom. After their victory, these kingdoms formed the World Government, which now controls much of the world. The World Government is responsible for the erasure of the Void Century from history, going to great lengths to suppress any information related to this period.
The only surviving records from the Void Century are the Poneglyphs—indestructible stone tablets that were created to preserve the truth of what happened during this time. These Poneglyphs are scattered across the world and are written in an ancient language that only a few can read. The Poneglyphs reveal the existence of the Ancient Weapons, the true history of the Void Century, and the location of Laugh Tale, the final island of the Grand Line.
The Void Century is also closely tied to the Ancient Weapons—Poseidon, Pluton, and Uranus—each of which has the power to cause massive destruction. These weapons were created during or before the Void Century and are believed to be capable of challenging the World Government's authority.
The Void Century is linked to the mysterious "Will of D.", a recurring theme in the series associated with individuals who carry the initial "D" in their names. These individuals are often seen as natural enemies of the World Government, and it is speculated that their ancestors were connected to the Ancient Kingdom.