George I. Gurdjieff embraced his "mysterious" origins and background (told imaginiatively in his book Meetings With Remarkable Men), and established several "Fourth Way" (i.e., contrasted with the way of the fakir, the way of the monk, and the way of the yogi) schools that purported to teach his students to "wake up"; i.e., experience a complete transformation of themselves through "the Work." His most famous student was occultic/mystical writer Piotr D. Ouspensky, who famously wrote of his experiences at Gurdjieff's school in his book, In Search of the Miraculous (Harvest Book), but later broke with Gurdjieff, establishing his own band of disciples.
Moore is quite candid in his 1991 book about the difficulty in "knowing" Gurdjieff; about the 1887-1911 period, for example, Moore writes, "Of Gurdjieff's history for the next twenty years or more we know everything and nothing." He produces some interesting insights into Gurdjieff, such as that "It is undeniable that Gurdjieff reverenced Christ."
Moore covers in some detail the break between Gurdjieff and Ouspensky (observing that Ouspensky effected the "wholesale repudiation of Gurdjieff and the wholesale appropriation of his ideas"), as well as Gurdjieff's near-fatal automobile accident (Gurdjieff admittedly "drove like a wild man").
Gurdjieff also wrote music, of which quite a bit is available The Complete Piano Music of Georges I. Gurdjieff and Thomas de Hartmann (6 CD Boxed Set).
Moore's book is highly interesting to those interested in the "Fourth Way" or other esoteric teachings, and is likely to remain the "standard" biography.