Safavid & Qajar Iran — Khaqan

Founder of the Safavid dynasty; his court poetry and royal titulature use Khaqan as an honorific reflecting his claim to supreme sovereignty; as a Turkic-speaking ruler of Persian lands, Ismail drew on both cultural traditions; his decisive victory over the Uzbek Shaybanids at Merv in 1510 — killing Muhammad Shaybani Khan — was celebrated in Persian qasidas addressing him as Khaqan

Longest-reigning Safavid Shah; received the Mughal Emperor Humayun at his court in 1544, and the correspondence between the two courts uses Khaqan as the standard honorific for both rulers — reflecting the title's shared recognition across the Persianate Islamic world; Ottoman–Safavid correspondence from his reign consistently uses Khaqan for the Shah in Persian-language documents

The greatest Safavid Shah; his court at Isfahan became one of the most sophisticated in the world; Abbas rebuilt the Safavid military and recaptured territories lost to the Ottomans and Uzbeks; Persian court poets addressing Abbas used Khaqan as his highest honorific in formal qasidas; his diplomatic correspondence with European powers (including England's Elizabeth I and James I) used the full Safavid titulature including Khaqan in Persian originals

Maintained the Safavid titulature including Khaqan in court ceremonial; his reign saw the continuation of the literary tradition of royal panegyric in which Khaqan featured as the supreme mark of imperial rank

Presided over a period of Safavid cultural flourishing; the Isfahan school of painting and architecture produced its greatest works under his patronage; court poetry addressing Abbas II uses Khaqan extensively in the Persian panegyric tradition

His reign saw the Safavid state's gradual weakening; nevertheless the ceremonial titulature and court literary tradition using Khaqan continued uninterrupted; correspondence with Ottoman and Mughal courts maintained the established honorific formulas

Last effective Safavid Shah; the Afghan Ghilzai uprising led by Mahmud Hotaki resulted in the fall of Isfahan in 1722 and the effective end of Safavid rule; court documents from his reign use Khaqan in the standard Safavid formula until the dynasty's collapse

Founder of the Qajar dynasty; reunified Iran after decades of post-Safavid fragmentation; his coronation documents and royal edicts establish Khaqan as an element of Qajar titulature in direct continuity with the Safavid tradition

His reign saw extensive court literary production; Qajar court poets, following the classical Persian qasida tradition, addressed Fath-Ali Shah as Khaqan in formal compositions; his diplomatic correspondence with Napoleon Bonaparte (1807 Treaty of Finkenstein) and with the British East India Company used the full Qajar titulature including Khaqan in Persian originals

Continued the Qajar use of Khaqan in official titulature; his two failed sieges of Herat (1837–1838) were occasions for court poetry using the full royal honorifics including Khaqan

The longest-reigning Qajar Shah; made three state visits to Europe and was the first Iranian monarch to leave detailed travel diaries; Western diplomatic correspondence addressed to Naser al-Din Shah translated Khaqan as 'King of Kings' or 'Emperor,' acknowledging its imperial rather than merely royal rank; his assassination in 1896 ended the longest continuous personal use of the Khaqan title in Iranian history

Signed the Iranian Constitutional Revolution's founding document in 1906 under popular pressure — one of the earliest constitutional revolutions in Asia; royal edicts from his reign maintain Khaqan in the formal titulature even as his political authority was progressively constrained by the new Majles (parliament)

Attempted to reverse the Constitutional Revolution by bombarding the Majles in 1908; deposed by constitutionalist forces in 1909; royal documents from his brief reign use the full Qajar titulature including Khaqan

Last Qajar Shah; his deposition by Reza Khan Pahlavi in 1925 ended the Qajar dynasty and with it the last continuous institutional use of Khaqan as a royal title in Iranian history; Ahmad Shah's final official documents, bearing the full Qajar titulature, represent the last use of the Khaqan title in Persian royal tradition