Prince Louis celebrates his sixth birthday with his parents Prince William of Wales and Catherine Princess of Wales, Kate Middleton and his siblings Prince George and Princess Charlotte in the UK. Louis is one of the grandchildren of King Charles III and is fourth in the line of succession to the British throne behind his father and siblings. 04 Mar 2020 Pictured: Prince Louis celebrates his sixth birthday with his parents Prince William of Wales and Catherine Princess of Wales, Kate Middleton and his siblings Prince George and Princess Charlotte in the UK. Louis is one of the grandchildren of King Charles III and is fourth in the line of succession to the British throne behind his father and siblings.,Image: 867116528, License: Rights-managed, Restrictions: NO Netherlands, Unknown Country, Model Release: no, Credit line: MEGA / The Mega Agency / Profimedia