It's brother against brother when Horus' traitors turn on their erstwhile comrades at the start of the Horus Heresy.
HAVING trouble wrapping your head around 40 millennia (and then some!) of continuity? Perhaps our condensed timeline of the Warhammer 40,000 universe can help....
Long before humankind existed: Two ancient races fought for control of the galaxy. Apparently, they both sort of lost. The “end” result was that one race, the Old Ones, had its power and influence forever shattered while its so-called doomsday weapon forced the other race – the Star Gods and their servants, the Necrontyr – into a 65-million-year slumber.
