One turn, the whole world is at peace, except for Malakim and Sheaim at war with one another. I research Feudalism, and things go nuts. Doviello begs to become my vassal, then Calabim. Malakim is highly advanced, but is down to one besieged city and in desperation begs to become my vassal. I agree.
Rhoanna declares war on Os-Gabella.
Mahala declares war on Os-Gabella.
Decius declares war on Os-Gabella.
Hyborem declares war on Rhoanna.
Hyborem declares war on Mahala.
Hyborem declares war on Decius.
Faeryl Viconia declares war on Rhoanna.
Faeryl Viconia declares war on Mahala.
Faeryl Viconia declares war on Decius.
Sabathiel declares war on Hyborem.
Os-Gabella declares war on Sabathiel.
Beeri Bawl declares war on Os-Gabella.
Hyborem declares war on Beeri Bawl.
Keelyn declares war on Beeri Bawl.
Cassiel declares war on Keelyn.
Auric Ulvin declares war on Keelyn.
Faeryl Viconia declares war on Cassiel.
Beeri Bawl declares war on Faeryl Viconia.
Sheelba declares war on Faeryl Viconia.
Dain the Caswallen declares war on Sheelba.
All in one turn LOL
edit: Of course, a few turns later Auric Ulvin demands that I give him the philosophy tech. Naturally I refuse, and he declares war on me, which set off a couple more DoWs, really solidifying this as a world war.