In 1847, Andrew Waugh, the British Surveyor General of India, found a peak in the eastern end of the Himalayas which was higher than Kangchenjunga, considered the highest peak in the world at that time.
Indian mathematician and surveyor Radhanath Sikdar was the first person to identify that Mount Everest was the world's highest peak as he was the first person to calculate the height of the mountain in 1852.
It was officially announced in March 1856.