When Bahá'u'lláh was nearly fifteen years old, His elder sister Sarih Khanum and Mirza Mahmud, the son of Mirza Isma'il-i-Vazir of Yalrud, were married. This Mirza Mahmud, who never espoused the new Faith, had a younger sister, Asiyih Khanum: winsome, vivacious and exceedingly beautiful. As soon as she came of age, and Bahá'u'lláh was nearly eighteen, Sarih Khanum requested her father, Mirza Buzurg, to ask the hand of this sister-in-law for her Brother, Mirza Husayn-'Ali. Their marriage took place in Jamadiyu'l-Ukhra (Jamadiyu'th-Thani) AH 1251 (about October 1835). Asiyih Khanum was the mother of 'Abdu'l-Bahá. (H.M. Balyuzi, Baha'u'llah - The King of Glory)