One of the most surprising facts to emerge from a survey of historical writing in this field is the almost complete absence of writers who have taken a stand outside the Christian tradition. Yet, on the other hand, it is often conceded that Christianity has had significance in parts of nineteenth- and twentieth-century Africa comparable with that which it possessed in Northern Europe. Belloc's dictum that 'Europe is the Faith, and the Faith is Europe' contains one of his wildest heresies; yet it remains true that a study of Christianity in Africa since 1800 must involve an analysis of the outside forces which produced so massive an intervention in the life of Africa. The dominant influence of the Sacred Congregation of Propaganda Fide, more perhaps than any other factor, sharply distinguishes nineteenth-century Catholic missionary activity in Africa from that of earlier centuries.