Reddit mentions of British cavalry uniforms since 1660

I'll have to pick two for this one as well, though this pair might as well be one volume: Michael Barthorp's British Infantry Uniforms since 1660 and its companion British Cavalry Uniforms- Combined, they are an incredibly comprehensive study of the development of British army uniforms. Barthorp gives an outline of historical events effecting the army in each chapter, and how those events in turn shaped the army's appearance. Both volumes are also lavishly illustrated with plates by the great Pierre Turner, examples of whose work can be seen here.