Born Mehdi Nuri, Mírzá Mihdí was the brother of Bahíyyih Khánum and ‘Abdu’l-Bahá. As the youngest of Bahá’u’lláh and Ásíyih Khánum’s children, he enjoyed his mother’s favor. Years later, Bahá’u’lláh gave Mírzá Mihdí the title “the Purest Branch.”
At the age of four along with his family, he joined his Father in exile in 1853. This was the first of successive exiles until finally, the band of nearly 70 exiles, arrived at the penal colony of Acre in Ottoman Palestine on 31 August 1868. There they were imprisoned in the barracks of the prison under the harshest conditions.
In the summer of 1870, while pacing on the rooftop of the prison, as was his custom while praying and meditating, Mírzá Mihdí fell through an open skylight to the floor below. He landed on a wooden crate that pierced his chest. His final wish to Bahá’u’lláh, as he laid dying, was that his life be offered up as a sacrifice to ease the suffering of his Father and to free His restrictions so that those that wished to attain His presence would finally be granted the opportunity.
At the time of his burial, there was an earthquake. In the following passage addressed to his deceased son, Bahá’u’lláh refers to the earthquake by stating, “”When thou wast laid to rest in the earth, the earth itself trembled in its longing to meet thee.”
(Bahá’u’lláh quoted in Shoghi Effendi, This Decisive Hour: Messages from Shoghi Effendi to the North American Bahá’ís, 1932–1946)