The Rocket Man hitmaker took to Instagram.com on Monday (18May15) to share images of the happy event, including a picture with his oldest friend from Pinner County Grammar School in north London and an image of the reunited class of 1958.

The British star also wrote a caption on the image: "Lunch at home with dear old school friends. Many of whom I haven't seen for 50 years! It was as if we never left school. So much laughter and so many wonderful memories... My oldest pal Keith Francis. A wonderful, loyal friend for 57 years and still counting! He flew all the way from Australia for our class reunion. Love you so much."