Cambridge University Press, 1975. - 711 pp.
Volume 4 is a survey of every aspect of the civilisations which
flourished in the Iranian region from the Arab conquests to the
Saljuq expansion: in particular, it studies the gradual transition
of Iran from Zoroastrianism to Islam, the uniting of all Iranians
under one rule, the flowering into full magnificence of the Persian
language, and the establishment of those other acts which were to
flourish so brilliantly after the Mongol conquest. The volume as a
whole provides a comprehensive record of the formative centuries of
Islam in Iran.