A Barha Sayyid's early service
The men of Sayyid Abdullah Khan's clan, the page records, had been "famous as military leaders" from the time of Akbar, and by their bravery "had acquired a traditional right to lead the vanguard of the imperial troops" (vol. I, p. 202). He himself — called Hasan Ali Khan before he inherited his father's title of Abdullah Khan — was son of a man who had likewise built a career in Mughal service: "Their father, Sayyid Abdullah Khan, known as Sayyid Miyan, had risen in the service of Ruhullah Khan, Alamgir's Mir Bakhshi," before attaching himself to Prince Muhammad Muazzam, later Bahadur Shah (vol. I, p. 203). Under Alamgir he himself held a string of faujdari charges in Khandesh before obtaining Aurangabad, and after a quarrel with Prince Muizz-ud-din the brothers quit the service and went to Lahor, "waiting for employment from Munim Khan, the nazim" of that place (vol. I, p. 203).
When the Mughal nobles weighed whether to back Prince Farrukh-siyar against Jahandar Shah, several held back; the page records that "There remained only the two brothers, Hasan Ali Khan (Abdullah Khan) and Husain Ali Khan, Sayyids of Barha, who owed to Azim-ush-shan the Governments of Allahabad and Bihar, which they then held" (vol. I, p. 201) — the offices that made the pair the last of Farrukh-siyar's possible allies still willing to commit to his cause.
Chief minister under Farrukh Siyar
That commitment carried Sayyid Abdullah Khan to the head of the new administration in 1713. On the march from Agra to Delhi after Farrukh Siyar's victory, the page records: "Sayyid Abdullah Khan (now made Nawab Qutb-ul-mulk, Yamin-ud-daulah, Sayyid Abdullah Khan, Bahadur, Zafar Jang, Sipah-salar, Yar-i-wafadar) became chief minister" (vol. I, p. 258), the senior post in the reorganised government that followed the fall of Jahandar Shah and Zulfiqar Khan.