Ahmad Niyaltigin was the treasurer of a sultan who rose to power by seizing what from his younger twin?
Mas'ud I of Ghazni Mas'ud I of Ghazni (Persian: مسعود غزنوی‎ ‎ ), known as Amīr-i Shahīd (امیر شهید ; "the martyr king")(998 – 17 January 1040), was "sultan" of the Ghaznavid Empire from 1030 to 1040. He rose to power by seizing the Ghaznavid throne from his younger twin Mohammad, who had been nominated as the heir upon the death of their father Mahmud of Ghazni. His twin was shortly blinded and imprisoned. However, when much of Mas'ud's western domains had been wrested from his control, his troops rebelled against him and reinstated Mohammad to the throne.
Ahmad Shirazi Khwaja Abu Nasr Ahmad (Persian: خواجه ابو نصر احمد‎ ‎ ), better known as Ahmad Shirazi (احمد شیرازی ), also known as Ahmad(-e) Abd al-Samad (احمد الکترونیکی عبد صمد ), was a Persian "vizier" of the Ghaznavid Sultan Mas'ud I and the latter's son Mawdud from 1032 to 1043. He was the son of the Samanid secretary Abu Tahir Shirazi, and had a son named Abd al-Hamid Shirazi, who would also later serve as "vizier".