The Nizams were the rulers of Hyderabad from the 18th through the 20th century. Nizam of Hyderabad (Niẓām ul-Mulk, also known as Asaf Jah) was the title of the monarch of the Hyderabad State (as of 2023 divided between the state of Telangana, Marathwada region of Maharashtra and Kalyana-Karnataka region of Karnataka). Nizam, shortened from Nizam-ul-Mulk, meaning Administrator of the Realm, was the title inherited by Asaf Jah I. He was the former Naib (suzerain) of the Great Mughal in the Deccan, the premier courtier of Mughal India until 1724, the founding of an independent monarchy as the "Nizam of Hyderabad".

The Asaf Jahi dynasty was founded by Mir Qamar-ud-Din Siddiqi (Asaf Jah I), who served as a Naib of the Deccan sultanates under the Mughal Empire from 1713 to 1721. He intermittently ruled the region after Emperor Aurangzeb's death in 1707. In 1724 Mughal control weakened, and Asaf Jah became virtually independent of the Mughal Empire; Hyderabad would then become a tributary of the Maratha Confederacy, losing a series of battles through the 18th century.

When the English East India Company achieved paramountcy over the Indian subcontinent, they allowed the Nizams to continue to rule their princely states as client kings. The Nizams retained internal power over Hyderabad State until 17 September 1948, when Hyderabad was integrated into the new Indian Union. The Asaf Jah dynasty had only seven rulers; however there was a period of 13 unstable years after the rule of the first Nizam when two of his sons (Nasir Jung,and Salabath Jung) and grandson Muzafur Jung ruled. They were never officially recognised as rulers. The seventh and last Nizam, Mir Osman Ali Khan, fell from power when India annexed Hyderabad in 1948 in Operation Polo.