Warhammer Homebrew Wiki

Although 'Warhammer' is the catch-all term for the universes that Games Workshop have developed through the years, each iteration of Warhammer is distinct from the others. Warhammer is split into two main universes, Warhammer Fantasy and Warhammer 40000, and each timeline has two main eras that could be summarily described as the 'past' and the 'present' of those universes.

In the case of Warhammer Fantasy, the 'past' era, formerly known as just Warhammer and now often referred to as “The Old World”, is set on an earth-like planet inhabited by various factions fighting for control and survival. Many of these have taken a clear inspiration from real world cultures, while others are interpretations of familiar concepts like elves, dwarves and orcs. This is also the setting where popular video games such as the Total War: Warhammer and Vermintide series are set. Central to the Old World is the struggle with the forces of Chaos, a battle that is ultimately lost leading to the 'End Times'. This event results in the destruction of the planet and a scattering of the eight winds of magic, each eventually congealing to a habitable pocket reality heavily shaped by that wind’s attributes. These eight realities are connected by realm gates and would be known as the Mortal Realms, forming the setting of Age of Sigmar, which is the 'present' era. This setting revolves around the survivors of the Old World, some of which have formed new factions shaped by the Mortal Realms in a struggle of survival.

As for Warhammer 40K, the 'present' era details the far future of our galaxy, where humanity rules a dying interstellar empire and battles for survival against numerous threats, both internal via rebellions and the insidious threat of Chaos, or external due to rival empires and faction of aliens. The timeline revolves around events that have occurred between the 31^st and 42^nd millennium, with the overwhelming majority having taken place in the 41^st. Much like with Warhammer Fantasy, many of the factions have taken inspiration from real world cultures, such as with the human factions or races such as the T'au Empire, or interpretations of familiar concepts like elves, dwarves and orcs, with a sci-fi twist. This is also the setting where popular video games such as the Dawn of War and Darktide series are set. The Horus Heresy meanwhile, covers the 'past', an era of cataclysmic betrayal where half of humanity's vaunted Space Marine Legions turned on the other, leading to all-out civil war. This event took place at the dawn of the 31^st millennium, at the end of a 200 year crusade to reclaim humanity's lost territories throughout the galaxy. It would herald the descent into madness and violence that is the norm of 40K, instigated by the titular Horus Lupercal - the favoured son of the Emperor of Mankind.