Nizam al-Mulk

Abū ʿAlī al-Ḥasan ibn ʿAlī Ṭūsī rose from a low post within the Seljuk ranks to become vizier, and when Sultan Alp Arslan was assassinated in 1072 he became the realm's de facto ruler for two decades. He formalized administrative policies and bureaucratic structures that shaped Perso-Islamic statecraft long after his death in 1092. His most visible legacy was the Nizamiyya system - madrasas he founded across the empire's cities, named in his honor. He is also traditionally credited with the Siyasatnama, a treatise that leans on historical anecdote to lay out principles of justice, effective rule, and the bureaucracy's place in Islamic governance.