"But of this genera of writing, William Muir's The Life of Mahomet, first published in 1861 in four volumes, was the best. It was a pioneering study and it has not been improved upon since then. William Muir had strong Christian views but he was also a painstaking and conscientious researcher, and he exhausted most of the sources on the Prophet's life, which were not many. The basic material on Muhammad is limited and new biographies could not really be new except in details, treatment and emphases."