I've never read anyone else who weaved together all of the Pali and Sanskrit literature so thoroughly. Fairly soon after Buddha's death Buddhism split into many schools. Chunks of the literature from these different schools still exist making the actual situation more complex than the usual idea that "the Pali Canon is oldest and everything else came later." Cheetham weaves together a single version of Buddhism from the variety of sources. It's a delightful job of reconstruction whether you agree with him on every point of not :) Well worth the read for any serious student, but not exactly the first book one should read on Buddhism.