I was playing the greek_cities in that example.

IsGeneral is the one who's in charge of the army, the way I understand it. He'll get all the traits from battles, etc.

This is how I'd do it:

edct:
Code:
Trigger GeneralCapturesRome
    WhenToTest GeneralCaptureSettlement

    Condition SettlementName Rome

    Affects GiveGeneralTrait  1  Chance  100
eda:
Code:
;------------------------------------------
Trigger trigger_someancillary
    WhenToTest CharacterTurnEnd
    Condition EndedInSettlement
          and SettlementName Rome
          and IsGeneral

    AcquireAncillary someancillary chance  100
This will give a trait to the general who captures Rome, and give the ancillary to any general who ends his turn in Rome. You could add
Code:
and Trait GiveGeneralTrait > 0
to the ancillary trigger to make sure only the conqueror gets the trait, and not just any general who sits in the city.