When did the office held by Donald Tsang from 2005 to 2012 come into being?
Donald Tsang: Donald Tsang Yam-kuen {'1': ", '2': ", '3': ", '4': "} (; born 7 October 1944) is a former Hong Kong civil servant and the second Chief Executive of Hong Kong from 2005 to 2012. Chief Executive of Hong Kong:  The office, stipulated by the Hong Kong Basic Law, formally came into being on 1 July 1997 when the sovereignty of Hong Kong was transferred from the United Kingdom to the People's Republic of China.
1 July 1997