*1962: Sino-Indian War; China seized Aksai Chin and overran Arunachal Pradesh.
*1967: There were two skirmishes between Indian and Chinese forces in Sikkim. The first one was dubbed the 'Nathu La incident,' and the other the 'Chola incident.'
*Chinese and Indian forces clashed in Arunachal Pradesh in 1986-87.
1988: Relations began to thaw. India and the People's Republic of China agreed to broaden bilateral ties in various areas, working to achieve a "fair and reasonable settlement while seeking a mutually acceptable solution" to the border dispute.
*1993: Prime Minister Narasimha Rao and Premier Li Peng signed the border agreement.
*1998: Sino-Indian relations hit a low point following India's nuclear tests in May. George Fernandes declared that "China is India's number one threat", hinting that India developed nuclear weapons in defense against China's nuclear arsenal.
*2004: The two countries proposed opening up the Nathula and Jelepla Passes in Sikkim which would be mutually beneficial to both countries.
*2006: China and India re-opened Nathula, an ancient trade route which was part of the Silk Road.
*November 2006: China and India had a verbal spat over claim of Arunachal Pradesh.
*2008: Prime Minister Manmohan Singh visited China and met with President Hu Jintao and Premier Wen Jiabao and had bilateral discussions related to trade, commerce, defence, military, and various other issues.
*January 2009: China also tried to block a loan from Asian Development Bank to India for the development of Arunachal Pradesh and when India succeeded in securing the loan with the help of USA and Japan, China expressed displeasure at ADB.
*2009: Chinese intrusion reported in Ladakh