The Prince and Princess of Wales have sent a special birthday message to King Charles via social media as he celebrates his landmark 75th birthday today (November 14).The post was shared with the couple's 14.9 million followers and contains three images of the monarch over the years, with a caption reading: "Wishing His Majesty The King a very happy 75th birthday!" The first photo shows Charles posing for a photograph with Prince William during a skiing trip to Klosters in 2004 - the same trip where he was first introduced to his future daughter-in-law. Meanwhile, the second is a solo image of the monarch taking part in an oak tree planting during his state visit to France earlier this year and the third is from Trooping the Colour back in June as the family gathered on the balcony of Buckingham Palace.