Mullá Hasan Bajistání was the sixth Letter of the Living. He was active at first in propagating the Bábí Cause and later retired to Karbala and considered himself unworthy of the station conferred on him by the Báb as one of the Letters of the Living. He visited Bahá’u’lláh in Baghdad between 1853 and 1863.
“Mullá Hasan Bajistání” Bahá’í Encyclopedia Project. baha’i-encyclopedia-project.org
Baha’i World Centre Archives – Door to the House of the Báb