jats:pDoes ideology prevent social movements from resorting to violence? Structuralist, organisational, or political economy theories are widely agnostic on the relationship between ideology and the use of violence. In contrast, this article argues that founding ideologies indirectly shape social movements’ long-run decisions regarding the use violence, primarily by influencing the kind of individuals who join the movement to begin with. A path dependency develops as new members reinforce the initial ideology, as individuals who might tip the ideological-organisational equilibrium towards utilising new tactics join other organisations instead. Over time, ideology morphes from being initially an endogenous factor into an exogenous constraint how the group can behave. The article compares the mainstream Egyptian Muslim Brotherhood (MB), al-Jama‘a al-Islamiyya (IG) and the Jihad Organisation (JO), studying individual biographies, the groups’ recruitment patterns and their corresponding ideologies. The article thereby explains why the MB, with some minor exceptions, remained committed to non-violent activism, in contrast with the JO that resorted to violent means only and the IG that applied both violent and non-violent means. In the conclusion, the article addresses cases in Algeria and Madagascar to indicate the relevance of this argument beyond Egyptian Islamist movements to future comparative work.</jats:p>