The centenary of the World Missionary Conference held at Edinburgh in 1910 has recently been celebrated. The Conference has been hailed as a decisive point in the rise of the modern ecumenical movement and in the history of mission. But there is a need for objective analysis of what the Conference achieved. This article examines the legacy of Edinburgh 1910 through the themes of unity and mission, exploring subsequent changes in attitudes and concerns in the four areas of secularization, empire, nationalism and gender. It suggests that the real achievements of the Conference have been obscured by the mythology that has grown up around it, and that a proper reception of the Conference requires much closer attention to the conditions that produced it than has conventionally been undertaken.