How Sikkim became a part of India

Sikkim is a state in Northeastern India. It is the least populous and second smallest state of India. Notable for its biodiversity, it is situated in the Eastern Himalayas. India got it's independence in 1947 but Sikkim joined the Republic of India in 1975. Before that, Sikkim was a independent Buddhist monarchy, ruled by the Chogyal (monarch).

It is said that Phuntsog Namgyal, founded the Sikkim's monarchy in 1642. He became the first Chogyal of the state. His son, Tensung Namgyal succeeded the throne in 1670. Sikkim faced many invasions after its establishment. In 1700, Bhutan invaded Sikkim but Tibetan people helped Sikkim save its sovereignty. There were multiple raids by Nepalese from the west and Bhutanese from the east.  In 1791, China helped Sikkim against invasion of Gorkha Kingdom of Nepal.

Cultural ties of Sikkim were with Tibet but eventually its ties with the British started getting strong, as they had Nepal as their common enemy. After the Gurkha war in 1814, Treaty of Titalia was signed between the Chogyal and British East India Company. According to it, Sikkim's area captured by the Gorkha Kingdom will be returned back and in return the Chogyal will let British to mediate with its neighbors. As parts of Sikkim was under the Gorkha Kingdom, there was a rise in Nepali Hindu population in the state.  The relation between then deteriorated when British EIC started taxation of Morang region (present day Nepal). Sir Joseph Dalton Hooker and Dr. Archibald Campbell were arrested by Sikkimese government in 1849 when they went to mountains of Sikkim unauthorized. It led to attack on Sikkim by the Britishers. At the end, Darjeeling (present day India) and Morang region exceeded into the British territory. Sikkim now became a vassal state of the Britishers and later in the 19th century, a protectorate.  

When India got independent in 1947, a standstill agreement was signed by Sikkim and Bhutan with the Indian government stating that they were not Indian states and their future will be negotiated separately. A pro-India and pro-accession political party, Sikkim State Congress (SSC) was formed which was working closely with Indian National Congress (INC). The monarch in response included three secretaries from SSC into his cabinet and started sponsoring Sikkim National Party (SNP) which against the idea of accession. In 1950, SSC launched massive protests and started civil disobedience movement. Chogyal (monarch) then asked for India's help. Finally, a treaty was signed between India and Sikkim which made Sikkim a protectorate of India. Sikkim's defense, external affairs and communication requirements were now under Indian government. Chogyal still remained a constitutional figure enjoying some autonomy in internal affairs.

In 1967, Chinese army infiltrated into Sikkim's territory in 1967. Sikkim being Indian protectorate, Chinese had clashes with the Indian army in the Nathu La and Cho La on 11 September. Indian government did not wanted to take any chances. There  was a rise in Chinese aggression towards Tibet and rising communism in Indian state of West Bengal. Also, Sikkim was performing well in terms of Literacy rate and per capita income in comparison to India and other neighboring countries. But, there were protests going on in Sikkim by Sikkim National Congress (SNC), asking for fresh elections and proper Nepali representation in the government. In 1973, things got worse and there were anti-royalist riots taking place in front of Chogyal's palace. 

When law and order got out of Chogyal's hand, he called the Indian government for help and on 8 May 1973, historical tripartite agreement was signed between The Chogyal, The Indian government and representatives of political parties of Sikkim (SSC, SNP, SNC). According to the resolution, a more democratic constitutions and greater legislative and executive powers of the elected representative of the people will be given. The responsibility for law and order was now in the hands of India. Following the May 8 Agreement, India sent a constitutional advisor to draft a constitution for Sikkim, to which the Chogyal objected. In April 1974 elections, pro-India Sikkim National Congress came into power.  There was a deep controversy in September 1974, when there were talks of drafting of a bill for merger of Sikkim with India. India on the other hand, made 35th Amendment in its constitution, terminating the protectorate status of Sikkim, and making it a Associate State.

In 1975, Sikkim's Prime Minister, requested the Parliament of India to make Sikkim a state of India. A military operation was launched by Indian army in the Chogyal's palace and within an hour they took over the whole city of Gangtok (capital of Sikkim). On 10 April, the Sikkim assembly adopted the resolution abolishing the institution of Chogyal and declared Sikkim a constituent unit of India. On 14 April 1975, a referendum was held in presence of Indian army on abolishing the monarchy. 59,637 (97.55%) votes were in favor of the resolution of total 61,133 votes. Indian parliament then gave final approval to make Sikkim a full fledged state on 26 April 1975 making 36th Amendment in the constitution. On 15 May 1975, Indian President, Fakhruddin Ali Ahmed, ratified the the constitutional amendment making Sikkim the 22nd state of India.