In two studies, we examined how perceptions of historical continuity affect group members' responses when their group is facing an upcoming merger. We found that perceived historical continuity was a unique predictor of resisting an upcoming merger between various army regiments in Scotland among those associated with the Black Watch (Study 1; N = 308) and those associated with a range of Scottish army regiments (Study 2; N = 498). We found that the perceived break with the past that the merger would involve mediated the relationship between historical continuity perceptions and merger resistance. However, we also found that when there was some reassurance that historical continuity of the pre-merger group would be preserved in the merged context (i.e. regiments could keep their pre-merger names), resistance to the merger was reduced (Study 2). We conclude that historical continuity perceptions can be a resource for groups that they will strive to protect in the face of future identity change. The findings underline the important role of group history perceptions in understanding present group dynamics. Copyright © 2010 John Wiley & Sons, Ltd.