In the early eighteenth century, Nadir Shah tore like a whirlwind across the Iranian plateau. The Safavid Empire, which had ruled Iran since 1501, had fractured. Nadir Shah picked up the pieces and, in a series of military victories, expanded Iranian domains well into present day Iraq and Afghanistan. His political abilities did not match his military acumen, though. His rule was marked by rebellion, and his empire disintegrated upon his death.
Tucker, a professor of Middle Eastern history at the U.S. Naval Academy in Annapolis, has written a masterful study of Nadir Shah, the first serious study of the Iranian leader published in English or, for that matter, in any language since 1938. He centers his study on Nadir Shah's reformulation of the shah's legitimacy. Nadir Shah's Safavid dynasty predecessors based their claim to rule on supposed lineage from the Seventh Imam. Tucker examines how Nadir Shah sought to create a new basis for legitimacy by redefining Iran's religious and ethnic heritage.
The Safavid dynasty had converted Iran to Shi‘ism beginning in 1501. Traditional Sunnis deny the legitimacy of Shi‘ism, which they see as based on false premises. The sectarian divide contributed to frequent warfare between the Sunni Ottomans and the Shi‘i Iranians. Nadir Shah, a Sunni, sought a new formulation. There are four main schools of Sunni thought; he proposed redefining Shi‘ism as a fifth school, albeit more divergent than the others. Soon after his 1736 coronation, Nadir Shah tried—and failed—to convince the Ottoman sultan—who had legitimacy in his capacity as guardian over Mecca—to recognize this formulation. The sultan declined although, in a 1746 treaty, he did recognize the Shi‘a as Muslims rather than heretics who had strayed from true Islam. Tucker traces Nadir Shah's attempts through a careful diplomatic history. Tucker finds that Nadir Shah's attempts to redefine legitimacy exacerbated a schism between the monarch and religious clerics and grew throughout the nineteenth century, manifested on occasion with open tension between ruler and clergy.
Less convincing are Tucker's conclusions—almost as an afterthought—that Nadir Shah represented a "modern" rule. Discussions of modernism are trendy in academic discourse but ultimately add little. An argument that Nadir Shah was modern because his rule represented such a sharp break with the past is disingenuous for such differences can be detected in almost any change of dynasty.
Easy-to-read, succinct, and well organized, Nadir Shah's Quest for Legitimacy incorporates Persian sources and fresh material from the Ottoman archives, making Tucker's study necessary reading for any serious Middle Eastern historian or Iranian specialist.
 See Laurence Lockhart, Nadir Shah, Shah of Iran, 1688-1747 (London: Luzac, 1938).