The Eclipse was a cyclic event in which Radiance, the Archon of the Faloran peoples, was turned incredibly vulnerable. In the most recent Eclipse, the Faloran Republic launched a crusade against Varantium, led by two members of its Triumvirate dictatorship and backed up by the cream of the Republican army. Their goal - to kill Radiance.
This crusade flaundered outside the walls of Falor, in part due to the betrayal of Renal Sistorian, but mostly because of the death of Pietro Gori of the Inquisition within the Cariapolis, where he came close to succeeding in his goal of Binding Radiance.
Before this Eclipse, the previous one saw the fall of the First Faloran Empire. The Palaienid Emperors saw that spirits had grown far more powerful than them in every aspect imaginable, and the Palaienid dynasty wished to reclaim sole rulership of the Empire. This led to the Last Emperor attempting to kill Radiance during the Eclipse, but his timing as poor, and he struck too early, leading to his death and the fall of the Empire.
Shatterbridge: Eclipse was a strategy and roleplaying game by Ashenmoon set during the events of the most recent Eclipse.