Prince William, Duke of Cambridge Attends the Tusk 25th Anniversary Ball at Syon House on September 17, 2015 in Brentford, England

Prince William, Duke of Cambridge arrives for the Tusk Trust conservation charity 25th Anniversary Ball, which honours the charity's impact in the midst of the continuing crisis facing wildlife in Africa, at Syon House on September 17, 2015 in Brentford, England

 Prince William, Duke of Cambridge makes a speech during the Tusk Trust conservation charity 25th Anniversary Ball, which honours the charity's impact in the midst of the continuing crisis facing wildlife in Africa, at Syon House on September 17, 2015 in Brentford, England 

Prince William, Duke of Cambridge makes a speech during the Tusk Trust conservation charity 25th Anniversary Ball, which honours the charity's impact in the midst of the continuing crisis facing wildlife in Africa, at Syon House on September 17, 2015 in Brentford, England 

The Duke of Cambridge is greeted by Joss Stone during the Tusk Trust conservation charity 25th Anniversary Ball which honours the charity's impact in the midst of the continuing crisis facing wildlife in Africa on September 17, 2015 at Syon House, Brentford, London.

The Duke of Cambridge is greeted by Joss Stone during the Tusk Trust conservation charity 25th Anniversary Ball which honours the charity's impact in the midst of the continuing crisis facing wildlife in Africa on September 17, 2015 at Syon House, Brentford, London.

 The Duke of Cambridge is greeted by Joss Stone during the Tusk Trust conservation charity 25th Anniversary Ball which honours the charity's impact in the midst of the continuing crisis facing wildlife in Africa on September 17, 2015 at Syon House, Brentford, London.

 The Duke of Cambridge with Joss Stone and CEO of Tusk Trust Charlie Mayhew during the Tusk Trust conservation charity 25th Anniversary Ball which honours the charity's impact in the midst of the continuing crisis facing wildlife in Africa on September 17, 2015 at Syon House, Brentford, London. 

Joss Stone and Prince William, Duke of Cambridge attends the Tusk Trust 25th Anniversary Ball at Syon House, Brentford, Middlesex, UK, on the 17th September 2015.

Prince William, Duke of Cambridge attends the Tusk Trust 25th Anniversary Ball at Syon House, Brentford, Middlesex, UK, on the 17th September 2015.

Prince William, Duke of Cambridge and Deborah Meaden  attends the Tusk Trust 25th Anniversary Ball at Syon House, Brentford, Middlesex, UK, on the 17th September 2015.

Prince William, Duke of Cambridge attends the Tusk Trust 25th Anniversary Ball at Syon House, Brentford, Middlesex, UK, on the 17th September 2015.

Charlie Mayhew and Prince William, Duke of Cambridge (R) ttends the Tusk Trust 25th Anniversary Ball at Syon House, Brentford, Middlesex, UK, on the 17th September 2015.

Prince William, Duke of Cambridge talks to guests including Theo Paphitis during the Tusk Trust conservation charity 25th Anniversary Ball, which honours the charity's impact in the midst of the continuing crisis facing wildlife in Africa, at Syon House on September 17, 2015 in Brentford, England 

Prince William, Duke of Cambridge with Joss Stone and CEO of Tusk Trust Charlie Mayhew during the Tusk Trust conservation charity 25th Anniversary Ball which honours the charity's impact in the midst of the continuing crisis facing wildlife in Africa on September 17, 2015 at Syon House, Brentford, London.

Prince William, Duke of Cambridge with Joss Stone during the Tusk Trust conservation charity 25th Anniversary Ball which honours the charity's impact in the midst of the continuing crisis facing wildlife in Africa on September 17, 2015 at Syon House, Brentford, London.