​This study traces the evolution of Hamas's military activities from its launch in 1987 to the development of its military wing (the Izz al-Din al-Qassam Brigades) after 1992, drawing on the memoirs and testimonies of the movement's political and military leaders in Palestine and on available data regarding military confrontations with the Israeli occupation. Having begun as a scattering of modestly armed and equipped groups – a form it still takes today in the West Bank – it has since evolved in Gaza into something resembling a regular army. It proceeds from the assumption that Hamas' military activities have developed in accordance with the changing nature of the Palestinian-Israeli conflict and of the movement's political thought (itself shaped by shifting relationships with the regional and international structures). This has given the movement a rather fluid identity which its interests and role in the region have led it to define primarily in terms of its military strength.