Hyderabad State
State · 1727–1947 CE · at its largest around 1744 CE
A large Deccan princely state founded by the Asaf Jahi Nizams, Mughal viceroys who became independent and later allied with the British; India annexed it in 1948.
On its lands while it lasted
- Great Trigonometrical Survey (1802–1871 CE): Survey that measured the Indian subcontinent by triangulation, beginning at Madras in 1802; it established the height of Mount Everest.
More on Wikipedia.