The thesis is concerned with an examination of Islam in Sri Lanka. It argues that while Sri Lankan Islam shares an ideology with the Islamic world, it has a specificity which may only be understood with reference to its particular historical and cultural context. As an Islamic community on the periphery of the Islamic world, Sri Lankan Muslims find their ideology, enduringly problematic. They must continually assert their egalitarian ideology, within the hierarchically ordered cosmological universe, that they share with Sinhalese Buddhists and Tamil Hindus. They must further assert their egalitarianism in the face of constant forces of stratification, internal to the Muslim community itself. Islamic ideology, given this particular cultural context, is both determining and constitutive of the community. The consolidation of the varied histories of the diverse Muslim community in the late colonial period is shown to be an aspect of hegemonic domination of the community by a fraction of it. The structure and force of Islamic ideology as revealed in Sri Lanka is discussed through an examination of religious understanding and ritual practice. The significance of the myths behind, and practices associated with, the shrines of the saints are explored and contrasted with those elsewhere in the Muslim world. Critical distinctions in the practice of Muslim saint 'worship' are discussed. The centrality of the mosque and the male religious community are examined, and the articulation of the mosque with the domestic order is clearly outlined. Sri Lankan Muslims elaborate, through their calendrical ritual, a constant regeneration of the Islamic community - ummah. At its most fundamental level this regeneration requires the unification of male and female, mosque and house. This practice is a constant metaphor of the original basis, and current practice, of the Sri Lankan Muslim community, founded by the marriages of Arab Muslims to indigenous women, in whose houses they took up residence. Regenerative symbols in this context are those of food and hearth, and feast practices reveal the constant constitution of the community through its rituals of communal commensality. The calendrical aspects of the regeneration are most readily determined through a discussion of the ritual complex surrounding Ramazan and culminating in the Feast of Sacrifice at the end of the Hajj. The ideological constitution of the ummah, at its various levels of incorporation, is examined from the perspective of the Sri Lankan Muslims. A perspective in which they as one of a multitude of specific, culturally and historically diverse communities of the Muslim world, participate in a calendrical ritual cycle, which they perceive at the ideological level, to embrace them all.