Summon History cost

When exactly player should announce cost of Summon History?

When the action is announced, the amount for X must be announced as well.

Keep in mind that you can announce X with a number higher than the blood on the acting vampire, which is relevant e. g. when he has (lives in ^^) the Ankara Citadel.

Hakuron wrote:

Keep in mind that you can announce X with a number higher than the blood on the acting vampire, which is relevant e. g. when he has (lives in ^^) the Ankara Citadel.

Also keep an mind that this only holds if you indeed have the Ankara Citadel on the minion (or something else that is already there that reduces the cost), since a minion has to be able to pay the cost in order to announce an action.