This chapter provides an introduction to the writings and utterances of ‘Abdu’l-Bahá (1844–1921), the son and successor of Bahá’u’lláh (1817–1892), the founder of the Bahá’í religion. Following a general discussion of ‘Abdu’l-Bahá’s sixty years of literary and oratory activity in the form of books, treatises, letters, prayers, poems, and speeches written or delivered in three languages, this chapter categorizes His work chronologically into four periods: I. 1863–1892, when, during Bahá’u’lláh’s lifetime, ‘Abdu’l-Bahá, acting as the de facto deputy of Bahá’u’lláh, wrote at Bahá’u’lláh’s instruction. Two of His major books and most of His exegetical writings were produced in this period. II. 1892–1910, the period from the beginning of His ministry to the time He embarked on His journey to the West. As the Centre of Bahá’u’lláh’s covenant, ‘Abdu’l-Bahá writings during this period, for the most part, focused on protecting the Bahá’í religion and preserving its unity. III. 1910–1913, when, as the interpreter of Bahá’u’lláh’s writings, ‘Abdu’l-Bahá expounded the principles of the Bahá’í religion in the talks and speeches He delivered in the West. IV. 1913–1921, the final seven years of His life, when His writings were devoted to issues with global implications and far-reaching consequences, such as peace, plans for the propagation of Bahá’u’lláh’s teachings, and fundamental philosophical questions.