The Nizams were the rulers of Hyderabad from 18th-through-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 2019 divided between the state of Telangana, Kalyana-Karnataka region of Karnataka and the Marathwada region of Maharashtra). Nizam, shortened from Nizam-ul-Mulk, meaning Administrator of the Realm, was the title inherited by Asaf Jah I. He was the viceroy of the Great Mughal in the Deccan, the premier courtier in Mughal India in 1724, and the founding "Nizam of Hyderabad".

The Asaf Jahi dynasty was founded by Mir Qamar-ud-Din Siddiqi (Asaf Jah I), who served as a viceroy of the Deccan under the Mughal Empire from 1713 to 1721. He intermittently governed 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 Empire, losing a series of battles through the 18th century.When the 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.