This essay explores the changing place of the 1641 rebellion in the memory cultures of Ulster loyalist communities before and after the Good Friday Agreement of 1998. Focusing on the loyalist centres of Portadown and West Belfast, I show that commemorative activities particularly flourished during periods of crisis in these communities as they moved (or were moved) towards compromise. The 1641 Depositions Project has argued that the 'memory' of 1641 must be replaced by 'history'. The potential for the transformation or dissolution of loyalist memories depends on the willingness of these communities to forget a long-established element of the expression of a 'besieged' Ulster Protestant identity, which in turn depends on their investment in the peace process. Nascent attempts to accommodate the history and memory of 1641 in post-conflict Northern Ireland suggest that perhaps the fledgling peace is not yet secure enough for such divisive memories to disappear.