Syed Abdullah Khan or Sayyid Mian, was the father of Syed Hassan Ali Khan and Syed Hussain Ali Khan the two famous Sayyid Brothers.
Sayyid Mian, was a loyal serviceman of Aurangzeb, he became famous as a commander during the Siege of Bijapur for planning the trenches and leading assaults during the Siege of Bijapur. Due to his services he was appointed the first Mughal Subedar of Bijapur.
He claimed to belong to the family of Sayyids or the descendants of the Prophet Muhammad through his daughter Fatima and son-in-law and cousin Ali who belonged to the Banu Hashim Clan of the Quraish Tribe.
References
Syed Mian Wikipedia(Text) CC BY-SA