From 1997 to 2017: Hong Kong's transition in pictures

HONG KONG, June 28 (Reuters) - On Saturday, Hong Kong will mark 20 years since the end of British colonial rule, when the Asian financial hub was handed back to mainland China.

The territory has seen tumultuous times since July 1, 1997, with economic turmoil, outbreaks of disease and more recently, pro-democracy protests casting shadows over the island, its stunning harbor and the New Territories up to the border with the mainland.

Hong Kong's reputation as a free-market haven was challenged during the 1997-98 Asian financial crisis, while the 2008 global financial crisis tested the health of its banks.

The city of 7.3 million people suffered badly during an outbreak of severe acute respiratory syndrome, or SARS as it is known, in 2003, when 299 people died from the flu-like virus.

It was also among the places hardest hit by bird flu.

A rush of money from mainland China vaulted Hong Kong into the ranks of the world's most expensive property markets. It also fueled public anger over high living costs and a widening wealth gap.

"My priority will be to heal the divide and to ease the frustration – and to unite our society to move forward," Chief Executive-elect Carrie Lam said in March after her selection by a 1,200-person election committee stacked with Beijing loyalists.

Chinese President Xi Jinping is due to attend anniversary events on the island in coming days, including Lam's swearing into office on Saturday as the city's first female leader.

Lam, 60, is the territory's fourth leader since it reverted to Chinese rule in 1997.

As part of the handover, a mini-constitution known as the Basic Law promised that Hong Kong would retain a high degree of autonomy under a "one country, two systems" formula, with full democracy an "ultimate aim."

But two decades later, there's no sign of that aim.

China declined to make any concessions to student protesters demanding universal suffrage in "Occupy" street demonstrations in 2014. Frustration among democracy activists has simmered ever since.

This picture package chronicles key moments in Hong Kong since its return to Chinese sovereignty after 156 years of British rule. (Writing by Darren Schuettler; Editing by Robert Birsel)