At the age of 21 , Prince William was appointed as a Counsellor of State ; he first served in that capacity when the Queen was in Nigeria attending the Commonwealth Heads of Government Meeting in 2003 . For his 21st birthday , William accompanied his father on a tour of Wales , visiting the Anglesey Food Fair and opening a centre for the homeless in Newport . By July 2005 , he embarked on his first solo overseas tour , travelling to New Zealand , to participate in World War II commemorations on behalf of Queen Elizabeth II in her role as Queen of New Zealand . For the 30th anniversary of his father 's charity The Prince 's Trust , William and his brother were interviewed together for the first time by television personalities Ant & Dec
Commonwealth Heads of Government Meeting
Commonwealth Heads of Government Meeting 2003
Prince William, Duke of Cambridge