This very important research based, comprehensive and most enlightening book is the revised and updated book combining my two most important books on Sri Sathya Sai Incarnation: Section I presents the second Sai Baba Incarnation - Sri Sathya Sai Baba's life (1926-2011), His Identityand Role, Teachings and His Contributions to humanity. It Is the revised and updated version of the author's first book 'Sai Baba Sai and His Message'(1975) which was very much appreciated by Sri Sathya Sai Baba saying: "...very good book, ...Yes,very good book." Its 13 editions were published from 1975 to 2002.. Section II presents a sample of Sri Sathya Sai Baba's thrilling miracles for which He has been universally known as 'Man of miracles'. His miracles are still happening throughout the world even after His leavingg His mortal body on 24th April,2011 at the age of 85.. In Section III is presented the author's own self-inspired life-long research review of the important writings of Sai devotees and scholars from various fields on this great incarnation of this age and His unique contributions to the moral and spiritual development and social welfare of millions of people throughout the world. It is a unique study as no one else has as yet done such a research review. This publication is being published on the happy occasion of His 90th Birth Anniversary on 23rd November 2015 as the tribute of the 80 year old author who has been privileged to be His ardent devotee for the last 40 years as His devotee since 1971 and studying His spiritual and social movement as a quasi observer retaining his Identity as an independent sociologist.