Bahá'u'lláh appointed his eldest son `Abdu'l-Bahá as the leader of the Bahá'í community (the Centre of the Covenant as this is called in the Bahá'í writings) and the sole authorised interpreter of his writings. `Abdu'l-Bahá whose given name was `Abbás was born in Tehran on 23 May 1844, the same day in the same year that saw the start of the mission of the Báb.
From the earliest years of his ministry, `Abdu'l-Bahá was opposed by his half-brother, Mírzá Muhammad `Alí. The latter claimed that `Abdu'l-Bahá was exceeding his authority. At first, Mírzá Muhammad `Alí succeeded in obtaining the support of several influential Bahá'ís. In the end, however, his opposition faded away and the overwhelming majority of Bahá'ís supported `Abdu'l-Bahá. This was undoubtedly mainly due to the clear and unequivocal text of Bahá'u'lláh's Book of My Covenant in which `Abdu'l-Bahá's appointment was made.
The main result of the opposition of `Abdu'l-Bahá's half-brother was the re-imposition of the strict terms of the original government orders of exile. This confined `Abdu'l-Bahá to the city of Akka for some five years. Eventually, as a result of the Young Turks Revolution in 1908, `Abdu'l-Bahá was freed. One of his first actions when freed was to complete the shrine of the Báb on Mount Carmel and to place the remains of the Báb there.
During the early years of `Abdu'l-Bahá's ministry, the Bahá'í Faith was taken to North America. By the turn of the twentieth century, there was a community of several thousand Bahá'ís in North America. Some small groups also arose in Europe. This was a very significant turning-point in the development of the Bahá'í Faith. It demonstrated that the Bahá'í Faith was capable of appealing to people outside the cultural world of the Middle East to which it had been confined up to that point in time. After he was freed in 1908, `Abdu'l-Bahá moved to Egypt for a while before setting off on the first of two journeys to the West. In the first journey in 1911, `Abdu'l-Bahá visited France and England. Then in 1912-13, he visited North America, Great Britain, France, Germany, and Hungary. In all these places he spoke at public meetings, in churches and before a wide variety of associations. He spoke on many of the issues of that time: peace, women's rights, racial equality, labour relations, etc. He met many prominent politicians, philosophers, artists, scientists, and leaders of thought and was the centre of a great deal of attention from newspapers and magazines.
`Abdu'l-Bahá returned to Haifa in 1913 and the following year the First World War broke out cutting off communications with the outside world. During these war years, `Abdu'l-Bahá wrote the Tablets of the Divine Plan, laying down his instructions for the world-wide spread of the Bahá'í Faith.
At the end of the war, the Haifa-Akka area fell to the British army and Palestine came under the British mandate. `Abdu'l-Bahá was much respected by the British authorities and he was eventually knighted for his services. `Abdu'l-Bahá passed away on 28 November 1921 and is buried in one of the rooms of the shrine of the Báb.