This article examines the tension between liberal peace-building and local political culture through the lens of party and personality politics in Timor-Leste. It argues that the efforts of the UN peacekeeping mission to promote multi-party democracy cut across the interests of two opposing political forces: the charismatic resistance leader, Xanana Gusmão, who was deeply suspicious of party politics and favoured supra-partisan coalitions; and the dominant political party, FRETILIN, which pursued majoritarian power. Over the 16 years since independence, FRETILIN maintained a strong party identity and the governments it led met strenuous opposition and came to a premature end, while the Gusmão-led or -backed governments formed and survived as pragmatic tactical alliances. The article concludes that although the UN peacekeeping mission guided institutional design to favour political party organisation as the foundation for achieving representational government, the institutions have subsequently evolved in response to local political drivers. While outside actors can seek to influence the formal rules of the game, local political culture will determine how the game is played.