Reason for Writing the Book, and for Whom It Was Written
As for the reason it was written, the author states explicitly in his introduction:
“This is a treatise comprising (1) comprehensive principles of divine governance and Prophetic administration.... It was prompted (2) by one of those in authority whom Allah has made it obligatory to advise. The Prophet—may Allah’s blessings and peace be upon him—said, as authentically reported from him through more than one chain: ‘Allah is pleased with three things for you: that you worship Him and associate nothing with Him; that you hold fast, all together, to the rope of Allah and do not become divided; and that you sincerely advise those whom Allah has placed in authority over you.’”
It is thus clear that the book was written because one of the emirs requested a treatise on this subject, either expressly—which appears more likely—or implicitly through his circumstances.
Who, then, was this emir? The title page of the Leiden manuscript (Lām)—described below—identifies the emir for whom the treatise was written. It reads: “The Book of Sharia Governance ... He penned it—may Allah have mercy on him—when Emir Qays (sic) al-Mansūrī requested it of him, and he acceded to his request. He wrote it in a single night; may Allah be pleased with him and make him well pleased.”
This is indeed how his name appears in the manuscript: “Emir Qays al-Mansūrī”! Yet no emir in Ibn Taymiyya’s time or thereafter was named Qays. I believe it most likely that the name is a corruption of (Āqush ...). It is also written Āqūsh, with a long ū. Apparently, the copyist found the name written as (Āqush), failed to read it correctly, and turned it into (Qays). The two written forms closely resemble one another.
He was Emir Jamāl al-Dīn Āqush al-Rahabī—with the letters rā and unpointed hā