The noble families of the Nur district, including Baha’u’llah’s family, had for generations provided the kings of Iran with well-educated government officials: civil servants who would collect taxes, keep accounts, pay the army and generally administer the government. Bahalu’llah’s father, Mirza Buzurg Nuri, rose in the ranks of these civil servants to become the minister to a royal prince who was the commander of the royal guards. He was later a vizier (minister), an official responsible for the collection of taxes, in a province. He was given the village of Takur in the Nur region in lieu of salary and he built a fine mansion there by the side of the Nur river as a family home. … Baha’u’llah’s father was also renowned as a calligrapher. Indeed, his real name was ‘Abbas and he had been given the designation Buzurg (meaning “great”) by the king because of his calligraphic prowess.
As was customary among Iran’s nobility, Mirza Buzurg had an extensive family. He took three wives and also had three concubines. The mother of Baha’u’llah was his second wife, Khadijih Khanum. She was from the Namadsab family of the village of Fiyul, a short distance south of Takur. This family had preexisting ties to the family of Mirza Buzurg since an older sister of Mirza Buzurg was already married into the family. Khadijih Khanum had been married before to certain Aqa Sultan and had three children from her previous marriage. With Aqa Buzurg she had five further children (two daughters and three sons; one son died while young). It was the custom of the family to spend the winter months in Tehran, where Mirza Buzurg would attend to his government duties, and the summer in the family home in Takur. Baha’u’llah, the fourth child, was born on 12 November 1817 in the family home in the Udlajan quarter of Tehran. His given name was Husayn ‘Ali but he is generally now known by the title he took in later life, Baha’u’llah (the glory of God).
(Moojan Momen, 'Baha’u’llah: A Short Biography')