Hilaire P. R. Belloc (1870-1953) was an Anglo-French writer and historian who became a naturalised British subject. He was one of the most prolific writers in England during the early twentieth century, known as an orator, poet, satirist, man of letters and political activist. He is most notable for his Catholic faith, which had a strong impact on most of his works and his writing collaboration with G. K. Chesterton. He was a noted disputant, with a number of long-running feuds, but is also widely regarded as a humane and sympathetic man. In this important book THE GREAT HERESIES written in 1936, Belloc predicts the re-emergence of Islam with mind-blowing accuracy, which we see in today's world, and expertly tackles all the other major heresies throughout history as well, which threatened to subdue true Faith.