Published here for the first time is much of a final and long-anticipated work on philosophy of history by the great Oxford philosopher and historian R. G. Collingwood (1889-1943). The original text of this uncompleted work has only recently been discovered. It is accompanied by further, shorter writings by Collingwood on historical knowledge and inquiry, selected from previously unpublished manuscripts held at the Bodleian Library, Oxford. All these writings, besides containing entirely new ideas, discuss further many of the issues which Collingwood famously raised in The Idea of History and in his Autobiography. The volume includes also two conclusions written by Collingwood for lectures which were eventually revised and published as The Idea of Nature, but which have relevance also to his philosophy of history. A lengthy editorial introduction sets these writings in their context, and discusses philosophical questions to which they give rise. The editors also consider why Collingwood left The Principles of History unfinished at his death, and what significance should be attached to the fact that it contains no reference to the idea of historical understanding as re-enactment. This volume will be a landmark publication not just in Collingwood studies but in philosophy of history generally.