Abdu'l-Bahá Abbas also known as Abbas Effendi, was the son of Bahá'u'lláh, the Prophet and Founder of the Bahá'í Faith. `Abdu'l-Bahá was appointed by His Father, to be the Center of the Covenant, sole Interpreter of the Holy Writings, and Perfect Examplar of the Bahá'í life.
Imprisoned at the age of 9, released in old age, 'Abdu'l-Bahá carried the Faith to the United States, Canada, and Europe on an extensive teaching tour in 1912. Bahá'ís frequently refer to Him as the Master, although He preferred the title 'Abdu'l-Bahá (Servant of Glory). At His death in 1921 His Will and Testament appointed His grandson Shoghi Effendi Rabbani as the Guardian of the Bahá'í Faith.
Another group, the Orthodox Bahai Faith, also recognizes Abdu'l-Baha as the center of the Covenant.