*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.'
*1986-87: Chinese and Indian forces clashed in Arunachal Pradesh
*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.