When did Rana autocracy begin in Nepal? How long did it last?

The last phase describe the authors was the succession of Juddha Shamsher to Prime Ministership in 1931 to 1951, the year Rana regime ended with Mohan Shamsher Rana, as the last Prime Minister of Rana Oligarchy which for 104 years reduced the Monarchy to a figure head of the Nepali state

Explanation

Rana era, (1846–1951) in Nepal, the period during which control of the government lay in the hands of the Rana family. Jung Bahadur (1817–77) seized power in 1846 and made himself permanent prime minister