‘Abdu’l-Bahá is the Son of Bahá’u’lláh. When He was born He was given the name Abbas. He was born in 1844 in Irán and died in 1921 in Israel. Bahá’u’lláh chose Him to serve as the Head of the Bahá’í community after Bahá’u’lláh died. He wrote 25,000 letters and gave lots of talks. Some of those are now available in English.