Coherence came rather from the common understanding of the English national past (the 'Whig' interpretation of history in the strict sense) which was diffused through all levels of the cultural community – writers, teachers, readers.
What made the series so successful was, above all, the colossal commercial advantage Penguin enjoyed at the time in its virtual world monopoly of serious paperback publishing."
The Pelican history was originally planned to comprise eight volumes covering the period "from the Roman invasion to the outbreak of the First World War".
[5] A decade later it was decided to add a twentieth-century volume, written by David Thomson and initially covering the period from 1914 to 1963, later extended to 1979.
[citation needed] Penguin commissioned other historians to revise the two books by Thomson and the one by Richmond, but the "now-dated series" was reaching the end of its useful life.