As in every other branch of learning, the study of the early history of Christianity has undergone massive changes during the last century. This has been due not only to the vast accumulation of knowledge through new discoveries, but to new approaches to the subject, together with the rise of archaeology as a principal factor in providing fresh information. The study of the early Church has as a result moved steadily from dogma to history, from attempts to interpret divine revelation through the development of doctrinal orthodoxy down the ages, to research into the historical development of an earthly institution of great complexity and of great significance in the history of mankind over the past two thousand years.