Margaret Thatcher, the Iron Lady of British politics who died on Monday at 87, played a key role in China's relationship with the United Kingdom, especially in the peaceful handover of Hong Kong, experts said.

Britain's first and only female prime minister, Thatcher died peacefully at the age of 87 after suffering a stroke, her family announced. She governed Britain from 1979 to 1990.

Chinese leader Deng Xiaoping met with then-British prime minister Margaret Thatcher in Beijing on Sept 24, 1982. Photo by Xinhua More photos: Archive pictures of Margaret Thatcher

"Margaret Thatcher played an important role in the development of UK-China relations. During the discussions over the handover of Hong Kong in the early 1980s, she came to recognize that it was important that the transition from British to Chinese rule should be smooth, and the diplomatic process was positive and productive as a result," said Rana Mitter, professor of Modern China at Oxford University.

"Although she was always determined to stand up for what she regarded as British national interests, she also understood the importance of pragmatism, and of good relations with China," Mitter said.

Tian Dewen, an expert on European studies at the Chinese Academy of Social Sciences, said Thatcher realized the importance of a rising China.

"Her visit to China and her decision to promote bilateral ties on economy and trade demonstrated to the Western world the necessity to communicate with China during the Cold War period, and Sino-UK relations have been on good terms since then," Tian said.

"She called for dialogue instead of confrontation with China in resolving the Hong Kong question, showing her vision as an outstanding politician," he said.

She was active in engaging with China and including it in the world system, which helped create a favorable international environment at a key period of China's reforms, he said.

Feng Zhongping, an expert on European issues at the China Institutes of Contemporary International Relations, said Thatcher was a realist in terms of Sino-British ties.

"Thatcher was very willing to develop relations with China," Feng said. "She had some concerns on settling the Hong Kong question at first, but after she visited China and talked to Deng Xiaoping, she changed her mind to facilitate a historic joint declaration between the two governments," Feng said.

Thatcher visited China four times, the first in 1977 as leader of the opposition.

During her subsequent visit in 1982, the first to China by a serving British prime minister, she met Chinese leader Deng Xiaoping and discussed the future of Hong Kong.

Cheung Chi-kong, executive director of the One Country Two Systems Research Institute in Hong Kong, said Margaret Thatcher might have made a wrong judgment from day one — when she decided to negotiate with Beijing.

She had underestimated China's persistence in sovereignty and national dignity, Cheung said.

Beijing was determined to resume sovereignty over Hong Kong, Cheung said.

After two years of negotiations, China and Britain released the Sino-British Joint Declaration in 1984, paving the way for Hong Kong's handover in 1997.