The rise and fall of Hong Kong's July 1 protests | See pics

July 1 is a glorious day in the eyes of China’s long-ruling Communist Party, marking the date that Britain returned Hong Kong to China in 1997.

In 2003, public opposition to a proposed national security law for Hong Kong swelled an annual protest held on July 1 to hundreds of thousands of marchers. A few months later, the Hong Kong government dropped the legislation, and the idea remained largely dormant for more than 15 years. Then last year, the central government in Beijing unveiled a surprise: a national security law it had drafted and quickly imposed on the semi-autonomous city. It took effect on the eve of July 1.