Wars of Iron and Blood

The Wars of Iron and Blood were a series of conflicts that followed the onset of the Sangheili's second industrial age circa the 20th century BCE, and ended roughly around the time the species rediscovered space travel two centuries later. The first examples of industrial-scale warfare in ages, the Wars of Iron and Blood saw a considerable death toll. Commonalities between these wars were few, and the concept is used more broadly to denote a period of history marked by its technology level, geopolitical upheaval, and widespread violence. Depending on the historian, there were between four and seven major wars, and numerous smaller ones.

In these wars, various clans and states on Sanghelios clashed for natural resources and ideology, with the cultural fallout of the Skyfall properly settling in for all regions of the planet. The worship of the Forerunners and the utter sanctity of Forerunner relics became standard during this time via conversion and conquest, as remaining holdouts of the pre-Skyfall order (now known as the Age of Decadence) were snuffed out. Around the start of the wars, the Sangheili remained at an industrial technology level, possessing basic firearms, hydrocarbon-powered engines, and basic aircraft they had managed to retain over the post-Skyfall dark ages. However, the arms race brought on by the wars saw the reemergence of various higher technologies, including jet engines and rockets, electronics and computing, as well as the eventual rediscovery of fission power and weaponry.

This period is generally considered to have ended around the time Sangheili space travel reemerged. A somewhat stable world order was formed for a time, allowing large-scale scientific and economic cooperation, eventually making it possible for the Sangheili to re-establish their interplanetary holdings in campaigns such as the Joorian Reconquest. Even space launches were a major source of dispute at this time, as some hardliners interpreted the Skyfall as the Forerunners' displeasure at Sangheili space travel. Despite this, more moderate voices prevailed and the Sangheili civilization took to the stars once again.