WASHINGTON, Aug 2 (Reuters) - U.S. House Speaker Nancy Pelosi was expected to visit Taiwan on Tuesday, drawing sharp warnings from Beijing, which claims the self-ruled island as its own territory.

Here are key developments in relations between the United States, China and Taiwan:

1949 - Mao Zedong's communists take power in Beijing after defeating Chiang Kai-shek’s Kuomintang (KMT) nationalists in a civil war. The KMT-led government retreats to the island of Taiwan, cutting off contact with mainland China.

1950 - Taiwan becomes an ally of the United States, which is at war with China in Korea. The United States deploys a fleet in the Taiwan Strait to protect its ally from possible attack from the mainland.

1954-1955 - The First Taiwan Strait Crisis: Beijing launches artillery attacks on some Taiwan-controlled outlying islands off China's southeastern coast. Taipei loses its control of some islands and moves remaining forces and residents to Taiwan.

1958 - The Second Taiwan Strait Crisis: Beijing launches months-long artillery attacks on the Taiwan-controlled outlying islands of Kinmen and Matsu, both close to mainland China. Taipei fights back with some U.S.-supplied weapons. China does not seize control of any Taiwan-held island.

1979 - The United States endorses the "One China Policy" and switches diplomatic recognition from Taipei to Beijing. Chinese leader Deng Xiaoping offers the concepts of “one country, two systems” and “peaceful unification” as possible alternatives to taking Taiwan by force.

1979 - The United States enacts the Taiwan Relations Act, which makes clear that the U.S. decision to establish diplomatic ties with Beijing rests upon the expectation that the future of Taiwan will be determined by peaceful means. It obliges Washington to help provide Taiwan with the means to defend itself.

1982 - U.S. President Ronald Reagan adopted Six Assurances to Taiwan, including a pledge not to alter the Taiwan Relations Act.

1995 - Taiwan President Lee Teng-hui visits the United States for a reunion at Cornell University, drawing criticism from Beijing and escalating tensions.

1996 - Third Taiwan Strait Crisis: Taiwan holds its first direct presidential vote. In reaction, Beijing launches missiles into waters near Taiwan; Washington dispatches aircraft carries to the region. Taiwan President Lee Teng-hui wins by a landslide in March.

2000 - Chen Shui-bian is elected Taiwan president, marking the first time in power for the Democratic Progressive Party (DPP), which supports Taiwanese sovereignty and formal independence.

2005 - Beijing adopts an anti-secession bill in March that makes secession by Taiwan illegal. In April, leaders of Taiwan's major opposition KMT and the Communist Party of China meet for the first time since 1949.

May 2008 - KMT-backed President Ma Ying-jeou, who favours closer ties with China, comes into power and sets aside political disputes with China to discuss deals ranging from tourism to commercial flights.

2016 - Tsai Ing-wen of the DPP wins the presidential race in January on a platform of standing up to China. In June, China suspends all official communications with Taiwan.

December 2016 - U.S. President-elect Donald Trump breaks decades of U.S. diplomatic precedent by speaking directly, by telephone, with President Tsai Ing-wen.

2017 - Trump administration approves $1.4 billion worth of arms sales to Taiwan, prompting anger from Beijing.

March 2018 - Trump signs legislation that encourages the United States to send senior officials to Taiwan to meet Taiwanese counterparts and vice versa, again infuriating China.

September 2018 - the U.S. State Department approves the sale to Taiwan of spare parts for F-16 fighter jets and other military aircraft worth up to $330 million, drawing a warning from China that it jeopardises cooperation between Beijing and Washington.

July 2022 - U.S. President Joe Biden and Chinese President Xi Jinping hold a two-hour call, where Biden underscores that “the United States policy has not changed and that the United States strongly opposes unilateral efforts to change the status quo or undermine peace and stability across the Taiwan Strait.”