The great majority of theological students in the English-speaking world can only read English. If such a one were to determine to investigate the critical development concerning Christian doctrine which took place in the fourth century of the Christian era, he would find himself very badly served. Recent books covering the whole story of the last stages of the formation of the doctrine of the Trinity are scarce, but they exist, and they are not in English. Much the best is Manlio Simonetti's La Crisi Ariana nel Quarto Secolo. There is also E. Boularand's L'Hérésie d'Arius et la foi de Nicée, which has some good points but generally is not satisfactory, if only because when Arius propounded his views they were not then formally heretical. In English the last full-scale book written on the whole Arian controversy was that of H. M. Gwatkin, Studies of Arianism, published in 1882. Twenty-seven years later he published the short Arian Controversy but in a note prefixed to it he says that this work is ‘largely, though not entirely, an abridgement’ of the earlier book. That book was a fine one in its day, but it is now almost completely out of date. The only other works that could be said to be comprehensive in approaching the subject are G. L. Prestige's God in Patristic Thought and J. N. D. Kelly's Early Christian Doctrines.