Q. The book "Taj-ul-masir" was written by whom?
Answer: Hasan Nizami
Notes: Taj-ul-masir was written by Sadruddin Mohammad Hassan Nizami in Turki language. The book deals with the political events in  North India from about 1192 AD to 1228 AD. It focusses on the reign of Sultan Qutub-ud-din Aibak ( founder of Slave dynasty)  and the early rule of Iltumish (son-in-law of Sultan Qutub-ud-din Aibak ).

16