Shah is a royal title of Persian origin that translates to "king." While it is primarily associated with the monarchs of Iran, the title has historically been used to refer to the leaders of various Persianate societies and non-Islamic kingdoms across different regions.
The title was applied to rulers of several historical entities, including the Ottoman Empire, the Khanate of Bukhara, the Emirate of Bukhara, the Mughal Empire, the Maratha Empire, the Bengal Sultanate, and various Afghan dynasties. It was also used among the Gurkhas.
In Iranian history, a monarch holding this title was often viewed as the successor to a lineage beginning with the original Persian Empire of Cyrus the Great. In this context, the more emphatic title Shāhanshāh was used since the Achaemenid dynasty. A roughly equivalent title, Pādishāh, was most widespread during the Muslim period in the Indian subcontinent.