OK, checking code:
Common events:
We have a barb horde with misfortune 1.
Knights at misfortune2 and era 2-3
Huge horde with misfortune 3
Necro with death 1, magic 2
Vine men with growth1, magic 1 and forest
Rare events:
Troglos with order 1 or lower
Vampire with magic 1
Villains if you have less then 20 units
Bogus, if not in the game already
Ronin if era 3 (was bugged, could only appear in era 20
)
Ermor attack max 5 dom
Marignon attack ermor
Hydra with heat 0+, swamp
Trolls in mountains
Ancient precense, no precense on the map, forest, growth 0+
Evil frost druid with cold 2 and forest
Pangaea worship with growth 3 and forest
Scorpion beasts in waste