1997: H5N1 bird flu jumps species barrier for first time, infecting 18 people; six die. All 1.54 million farmed poultry culled.
2001: Second outbreak among poultry in wet markets; 1.37 million birds culled.
2002: Outbreak on chicken farms; 919,000 birds culled.
Dec 2002 to mid-2003: Wild fowl in Penfold Park, Sha Tin, die of H5N1, which spreads to farms; poultry at affected farms culled.
2003: Donald Tsang Yam-kuen, as chief secretary, lists a central slaughterhouse for poultry as a priority.
2004: The government offers compensation to chicken vendors if they are willing to surrender their licences.
2006: A central poultry slaughterhouse will be built in Sheung Shui and will be operational in 2009 at the earliest, according to the government.
2008: Government says central slaughtering facilities to be scaled down. Starts second round of buyouts of chicken-vendor licences.
2010: Central slaughtering plan officially shelved.