Shoghi Effendi Rabbani was born in Akka (Acre), in Ottoman Palestine, in 1897, the eldest grandson of Abdu'l-Baha and great-grandson of Baha'u'llah. He studied at the American University of Beirut and then at Balliol College, Oxford, where he was reading for a degree when Abdu'l-Baha died in November 1921. Returning immediately to Haifa, he learned that Abdu'l-Baha's will and testament named him Guardian of the Baha'i Faith and the sole authorized interpreter of its sacred writings, an office created for him alone and not repeated after his death.
His first and most lasting labor was translation. Baha'u'llah and Abdu'l-Baha had written in Persian and Arabic, much of it in a dense, allusive prose that earlier renderings had not carried into English successfully. Shoghi Effendi produced the English versions of the Kitab-i-Aqdas, the Kitab-i-Iqan and the compilation Gleanings from the Writings of Baha'u'llah that Baha'i communities still use, choosing a deliberately formal, scripture-register English he judged suited to the material. He also wrote God Passes By, a history of the faith's first century, and thousands of letters to individual believers and national communities that themselves became a body of interpretive literature guiding practice and belief.
He held the guardianship for thirty-six years, a period in which the Baha'i community grew from a following concentrated in Iran and the Middle East into a religion established on every continent, before his sudden death in London in 1957.