The Eras of the World

The history of this world is divided into eras. When a sufficiently large enough event happens to change the status quo of the world, a new era is declared. We are currently on the fourth era post war.
First Era: Lasted 1026 years. Started with the end of the Great War, ended with the fall of the Alutarian Empire.
Second Era: Lasted 3882 years, ended when the Planar Colonies were founded and the World Gates erected, naming the Third Era the Era of Exploration.
Third Era: Lasted 250 years, ended with the Planar Revolt, which resulted in the destruction of the World Gates and thousands of deaths.
Fourth Era: Has so far lasted 1750 years.