London - Prince William may be the president of the English Football Association he has wished Wales well in their Euro 2016 semi-final against Portugal on Wednesday.
William, second in line to the British throne, said both he and his brother Prince Harry would be watching the semi-final on television.
In a good luck message to the Wales team, William congratulated Chris Coleman's men "for progressing much further than England did!" England succumbed to a shock defeat by Iceland in the last 16.
William, known officially as the Duke of Cambridge, would succeed his father, Prince Charles, as Prince of Wales should his father become king.
In recognition of this future role, William is a vice-patron of the Welsh Rugby Union.
In his message, he praised Wales' "togetherness, passion and sense of self-belief", saying this was "unmatched" by any other side at Euro 2016 in France.
"Harry and I will be watching the game from home tonight, cheering you on. We are all now celebrating your success, and hope it continues through to the final."
In a typed letter, with "To Chris and all the Welsh Team" handwritten at the top, William said the squad should go into Wednesday's game in Lyon "knowing that you have delighted thousands of new fans, in addition to the joy already brought to the millions of steadfastly loyal and incredibly vocal supporters you had before."
He ended his letter with the motto "Cymru am byth!" which translates into English as "Wales Forever".
Meanwhile Charles, better known for playing polo than being a football fan, also sent a good luck message to the Wales squad.
He said Coleman's side had been "inspiring".
"As you prepare for what will be -- so far -- the most important night in the history of Welsh football, I did just want to send you all my special thoughts and wishes," he wrote.
"Throughout the whole championship, you have set an inspiring example of teamwork and sportsmanship and I have no doubt that in this latest game you will continue to give your country even greater cause for pride.
"Your historic achievements have already earned the support not only of Wales, but of the whole United Kingdom, and I hope you will know just how much we are all willing you on to further success."
Earlier this week, Charles joked he was surprised anyone had come to see him open a new university campus in Swansea, as he thought everyone in Wales "had gone to France" for the football.
Wales or Portugal will face hosts France or Germany in Sunday's final in Paris.