The Indian Ocean since ancient times was an important goe-strategic arena of inter-regional unities held together informally by trade winds and diplomatic relations. In the geographical and historical convergence of East and West, Asians, Africans and Europeans interacted with one another over a period of many centureis, participating in a sophisticated structure of commerce and politics underpinned by the system of monsoons. It was therefore only a matter of time before the 'balanced' geography of the Indian Ocean gave rise to balances of power. But when exactly, and how, did the geo-strategic, inter-regional character of the Indian Ocean translate into maritime balance-of-power considerations? This paper explores the historical roots and changing dynamics of that geopolitical equation. In so doing, it evaluates the evolving matrix of intra-regional and extra-regional players as well as the comparative importance of varieties of power in the Indian Ocean arean: 'hard' or 'soft', 'state' or 'non-state', 'land-based' or 'seaborne'. The paper then examines some of the long-term implications of these changing balances for the future of the region-especially in view of the present, concurrent rise of India and China.