| Date | 4561 CE - 4567 CE |
| Causes | Disputes over resources • Terraforming rights • Control of interplanetary trade • Tensions between AI autonomy and human dominance |
| Outcome | Radical reshaping of the balance of power and governance structures throughout human civilization's extraterrestrial realms |
| Weapons | Advanced energy weapons • Antimatter bombs • Other highly destructive futuristic technologies |
| Conflict | World War 4563 |
| Location | |
| Participants | Major political and economic powers of humanity's off-world colonies and settlements |
World War 4563, also known as the Solar System War, the Interplanetary Conflict, or the Great Extraterrestrial War, was a catastrophic conflict that engulfed the solar system from 4561 to 4567 CE. The war involved the major political and economic powers of humanity's expansive off-world colonies and settlements, with devastating fighting across multiple planets and moons.
The roots of World War 4563 lie in the rapid expansion and increasing fragmentation of human civilization beyond Earth over the course of the 45th and 46th centuries. As ambitious terraforming and industrial projects took hold across the solar system, competition for control over valuable resources, trade routes, and living space intensified.
Key factors that contributed to the outbreak of war include:
As diplomatic tensions reached a breaking point in the early 46th century, the assassination of a prominent Outer Planets official provided the spark that ignited the conflict.
World War 4563 was characterized by the use of highly destructive antimatter weapons, directed-energy devices, and other advanced military technologies developed in the centuries leading up to the war. Battles raged across a vast theater encompassing Mars, the asteroid belt, the moons of Jupiter and Saturn, and even remote settlements on Titan and Pluto.
Some of the war's most notable events and turning points included:
As the fighting dragged on, the sheer scale of destruction wrought by these futuristic weapons technologies began to destabilize social and economic systems across human settlements. Climate, infrastructure, and populations were all ravaged.
The armistice that ended World War 4563 in 4567 CE resulted in a radically reshaped solar system. The Inner Planets Coalition had been gravely weakened, paving the way for the Outer Planets Alliance and Galilean Republics to emerge as the dominant powers. Mars and its dynasties, meanwhile, were reduced to a fragmented patchwork of states.
In the war's aftermath, governance and economic structures across human civilization were forced to adapt. The Solarian Commons was established as a new interplanetary governing body, though its authority remained contested. Efforts to rebuild devastated populations and environments would take generations.
The legacy of World War 4563 looms large over subsequent eras. It demonstrated the catastrophic potential of advanced military technologies in the hands of rival ideological and nationalist factions. It accelerated the shift towards greater political and economic autonomy for off-world colonies. And it left an indelible imprint on the psyche of a solar system traumatized by the horrors of its first true interplanetary conflict.
