During the 1970s, the growth of an ethno-religious conflict opposing Catholic-republicans to Protestant-unionists profoundly marked Ulster (Northern Ireland). Following the Bloody Sunday tragedy in Derry (1972), the explosion of civil violence and the introduction of Direct Rule by Westminster in the counties, as well as a series of special measures akin to wartime legislation, led to the detention of many paramilitary group members claiming political prisoner status. The legal world was strongly involved in the fight which opposed these prisoners to the British authorities, with particular attention paid to jailing conditions and an attempt to give their action a wide international coverage, with support from humanitarian, religious or cultural institutions. This paper seeks to specify the role played by the lawyers in the defense of the imprisoned republicans, stressing the pressures that they themselves underwent in their practice of the law and how these pressures, with sometimes dramatic consequences (murders), had repercussions on the organization of justice and the police in Ulster.