Crusading masculinities could take many forms, but most were related to the roles the man in question was expected to perform. The leader of a crusade was subject to certain gendered expectations of social status, and martial prowess. However, when incapacitated by ill-health or bodily failure and unable to perform his allotted role, his position could be compromised. Not only could this be problematic for the masculine identity (and reputation) of a crusading leader, but could also jeopardise the crusade and those he led in it. Crusader chroniclers frequently dwelt on the health of crusader leaders and in these records masculinity, kingship, nobility, leadership and martial ability are bound up as identities in crisis, compromised by health. This essay examines the depiction in crusader chronicles of the illnesses of key crusader leaders from the twelfth and thirteenth centuries in order to consider how illness could put the masculine identity of a crusader leader at risk and the consequences—both military and reputational—for him and those who followed him.