The Arkfall is the name given to the arrival of the Incû-Holoinas upon the World. This is the most significant event in recorded history, sparking the Cûno-Inchoroi Wars, the near-ruination of Nonman civilisation, the arrival of Men in Eärwa and ultimately the onset of the Apocalypse.
The Arkfall was heralded by a sudden waxing of the star Imburil, which men later called the Nail of Heaven. The star burned with remarkable ferocity for a brief period before returning to normal. Three years later, Arkfall took place.
The Incû-Holoinas was a spacefaring vessel containing the dread Inchoroi. According to some reports, the Ark had visited numerous worlds and unleashed destruction on a titanic scale on each occasion before resuming its journey. It is unclear if the Ark had landed on each world or merely visited destruction from above each time. The reason for the Ark's uncontrolled descent onto the World is unknown, although the Inchoroi did report it as an unintended accident.
The Ark's arrival in north-western Eärwa visited enormous destruction upon the planet. An immense crack, known as the Displacement, was riven straight through the Nonman stronghold of Ishterebinth and the foundations of Cil-Aujas, over two thousand miles away, were briefly shaken. The skies turned red over the continent. However, the most devastating impact was felt in Viri, the Nonman Mansion located closest to the catastrophe. The verdant forests and plains in Viri's western Reach were completely destroyed, and the walls of the Mansion were scorched by the heat. All of the lands between the River Sursa and the Yimaleti Mountains were laid waste, becoming a desolate, utterly lifeless plain known as the Agongorea, or Field Appalling.
Tens of thousands of Nonmen alone were killed in Viri by the earthquakes and tremors unleashed by the Arkfall. The death toll amongst the Halaroi, the vassal-men of Viri, was certainly far greater. The destruction of Viri's farmlands and supplies resulted in King Nin’janjin calling upon Cû’jara-Cinmoi of Siöl for aid. Cû’jara-Cinmoi invaded and occupied Viri and sent the great warrior Ingalira to investigate the cause of Arkfall.
Ingalira reported that a great molten lake had formed on the site of the cataclysm, with two immense golden horns towering many thousands of feet into the sky. He also found two survivors of the crash, creatures of obscene aspect who made noises devoid of meaning. He dubbed them "Inchoroi", or "People of Emptiness". Cû’jara-Cinmoi ordered the two wretches executed on the spot. These events eventually led to the Inchoroi-Viri alliance, the Battle of Pir Pahal and the Cûno-Inchoroi Wars that would consume the fate of the Nonmen for the next several centuries.
The Arkfall took place a considerable amount of time before the Breaking of the Gates, the arrival of the Four Tribes in Eärwa and the overthrow of Nonman civilisation. According to the The Chronicle of the Tusk, the Breaking took place 4,132 years before the Great Ordeal began its march on Golgotterath. The length of time that elapsed between Arkfall and the Breaking is difficult to fathom. At least one Nonman who lived through the period stated that eight thousand years have passed in total (four thousand years before the Breaking), but given his Erratic nature the accuracy of this figure is highly debatable.