A timeline of the pro-Democracy movement in Hong Kong since 1984:

December 1984: Britain and China sign a Joint Declaration in which terms of Britain's 1997 return of Hong Kong to China are outlined. The 1984 Sino-British power transfer agreement specifies that China will allow Hong Kong a “high degree of autonomy” for 50 years. Beijing calls this “one country, two systems."
June 3-4, 1989: Chinese troops fire on protesters in and around Tiananmen Square after weeks of pro-democracy demonstrations. The military action rallies more than a 1 million people in Hong Kong to call for democratic safeguards to be put in place in the territory.
April 1990: Beijing ratifies Hong Kong's Basic Law, a mini-constitution that calls for "universal suffrage” in the territory.
July 1997: After 150 years, Britain returns Hong Kong to China. Beijing names a Shanghai-born, former shipping magnate, Tung Chee-hwa, as the territory’s first post-British head of government.
February 2001: Hong Kong's number two official, Chief Secretary Anson Chan, opposes Chinese interference in the territory's affairs, and resigns under pressure from Beijing.
April, 2004: China rules out the possibility of universal suffrage in Hong Kong in 2007 and 2008. China also says Beijing must approve any changes to Hong Kong election laws, giving China virtual veto power over Hong Kong’s evolution toward democracy.
December 2007: Beijing says Hong Kong can directly elect its own leader in 2017 and its own legislators by 2020.
September 2012: Tens of thousands of students besiege a government building for 10 days, to protest a proposal that would require Chinese identity lessons in Hong Kong schools. Hong Kong's Chief Executive Leung Chun-ying is forced to scrap the plan.
June 2014: Nearly 800,000 people vote in an unofficial referendum calling for open nominations in Hong Kong's 2017 election. The protest is deemed illegal by Hong Kong's government and Chinese officials.
July 2014: Hundreds of thousands of pro-democracy protesters march through Hong Kong calling for a genuinely democratic vote in 2017. Police arrest more than 500 of them after protesters stage an overnight sit-in in the main business district.
August 2014: Anti-corruption officers raid the home of a prominent media magnate who is an outspoken critic of Beijing. Jimmy Lai has supported pro-democracy activists in Hong Kong through his publications and financial contributions.
August 2014: The Standing Committee of China's National People's Congress rules out a fully democratic election for Hong Kong's leader in 2017. The Chinese impose tight rules on the nominating process.
Sept. 2014: Thousands of pro-democracy protesters stage huge rallies in Hong Kong, demanding that China allow free elections.