“Presumably with the same elaborate detail and conscientious pursuit of accuracy, not only in minute particularities of reference to multitudinous authors, but in the philology of all Oriental terms employed. But the list quoted includes a range of reading so extensive that, the Introduction alone will entail a research as exhaustive, and employ a period as considerable, as that which has already engaged his diligence. The work is a rich storehouse of raw material to be used by future labours in the same field. It is a work of a scholiast … wherein the technical terms relating to the personnel of the army, its equipment, arms, munitions, methods of attack, defense, and the like, are discussed under separate headings, with much learning. Would do justice to the industry and ability which he bring to his task.” Extract from the Book Review by H. S. Jarrett, published in the Journal of Royal Asiatic Society of Great Britain and Ireland. In India Irvine was known as an authority on the provincial laws of rent and revenue. In 1868, while still an assistant, he published his Rent Digest, a digest of the rent law of the province. In 1879 he produced a history of the Afghan Nawabs of Fatehgarh or Farrukhabad. On returning to England he began a history of the decline of the Mogul empire, planned as from the death of Aurangzeb in 1707 to the capture of Delhi by Lord Lake in 1803. Chapters appeared in the Journal of the Asiatic Society of Bengal between 1896 and 1908, though history itself was not carried later than the accession of Mahomed Shah in 1719. Related papers appeared in the Journals of the Royal Asiatic Society of London and the Asiatic Society of Bengal, the Asiatic Quarterly Review, and the Indian Antiquary. Irvine published the longest and most ambitious work The Army of the Indian Moghuls: its organisation and administration, in 1903 the work on which began in 1896, being impelled by the belief that some information of the kind was a necessary introduction to a History of that period. The book still remains a go-to treatise on the subject. Irvine also contributed in 1908 the chapter on Mogul history to the new Gazetteer of India. His last significant publication was a life of Aurangzeb in the Indian Antiquary for 1911; a résumé appeared the same year in the Encyclopédie d’Islam.