Event gives you army attacking random enemy prov?

[LoloMo]

Hi, In an MP game I'm playing as LA Ermor, I suddenly got a message that I was attacking an enemy province maybe 7 steps away from my borders. I looked and saw 5 Ermorian Cultist (level 1 priest) and about 20 souless.

I did not receive any event notification, just that message that I was attacking someone. I also have 4 dominion in the conquered province.

Does anyone know what triggers this? Is it a lucky event?

[Velusion]

It is a lucky event. I've had it happen before when playing LA Ermor.

[LoloMo]

Thanks! I wish I have more of those, but way on the other side of the map =)