Following the theme of early pietist literature in the Islamicate kingdoms this paper analyzes the theme of philosophy of governance as exemplified in one of the most prominent examples of early Islamic pietist literature: the Nahj al-Balaghah, a collation of lectures and epistles supposedly authored by the fourth Caliph ‘Ali ibn Abi Talib and collected by the tenth century CE scholar Sharif al-Razi. In particular this paper contributes to the extremely limited history of English-language scholarship of the highly-influential epistle within the Nahj al-Balaghah titled “The Letter to Malik al-Ashtar” in which the Caliph outlines a remarkably detailed and systematic philosophy of governance for his soon-to-be deputy in Egypt, Malik al-Ashtar. This paper makes the first attempt to extract from this epistle, not merely a theory of ethics, but rather a concrete theory of piety-based political philosophy and governance itself. The theories of governance espoused in this text are of unparalleled specificity in the annals of early Islamic history, yet, almost no English-language literature as of yet has moved beyond the subject of ethics to explore the actual themes of politics it reveals in ‘Ali’s thought. ‘Ali ibn Abi Talib’s unique theory of governance, which this paper gives the name of “Theological Populism”, relies on an entirely innovative marriage of Islamic theological premises with a form of non-demagogic populism to construct a religiously-binding and authorized approach of governance-for-the-people. As an authoritative model for Islamic and particularly Shia communities, the egalitarian and ethical nuances of ‘Ali’s philosophy holds tremendous value for Islamic nations of the 21st century seeking to define their own unique theories of government based not only on modern rational values but also the traditional Islamic sources of revelation. Fleshing out this remarkable theory in detail, this paper not only unveils the framework of this theory but uses the results of a new, in-depth study of the Letter to Malik al-Ashtar to offer strong new arguments for the epistles disputed authenticity.