It was their first visit in over a year - and it could go down in history as the first step towards reconciliation.
And GB News’ Royal Reporter Cameron Walker was the first to break the news on air that Prince Harry and the King’s meeting on had officially taken place.
Cameron’s scoop came just weeks after he exclusively revealed Prince Harry had secretly left a letter at the National Memorial Arboretum to mark Victory in the Pacific Day.
Similar world beating success was also seen on GBNews.com, where the royal team broke the news of Wednesday's reunion in tandem with Cameron's scoop - delivering the key facts to the site's loyal readership first, ahead of all other digital competitors
The stories underline GB News as the king when it comes to breaking the best coverage for the latest Royal news.
How GB News led the world on coverage of King Charles and Prince Harry's meeting
Here, Cameron shares his insight on yesterday’s meeting:
“We knew it was a possibility that King Charles and Prince Harry would meet at some point this week, despite both offices refusing to comment on any such meeting.
"In fact, one close aide revealed to me they had asked their principal not to tell them if a meeting was taking place, so they didn't have to withhold golden information from the media and damage trust.
"So, GB News and our counterparts at other networks were left to revert to good old-fashioned journalism: investigating, scoping out locations, and verifying.
"Firstly, it's very obvious to spot when King Charles is at his London residence; the Royal Standard is raised.
"His Majesty arrived at Clarence House around the same time Prince Harry finished an engagement at Imperial College London,
so we knew there was a window ahead of the Invictus Foundation reception, which Prince Harry was due to attend.
"Working together, the UK media had teams of photographers, correspondents and television cameras waiting on both entrances of Clarence House - constantly communicating with each other for any sign of movement.
"Then, it was a waiting game. For more than an hour.
"Just when we thought all hope was lost, at about twenty past five in the afternoon, a colleague shouted: "That looks like Harry's car."
Cameron continued: "I looked: 'No, that IS Harry's car!'
"Photographers dashed to snap pictures, and we alerted our colleagues on the other gate to the fact Harry's car was inbound. I hadn't physically seen Prince Harry, only his car, so I couldn't verify.
"Luckily, a team from another network provided confirmation.
"Having prepared thoroughly for a 'Charles meets Harry' scenario, our One GBN plan sprang efficiently into action, meaning we were the first media organisation in the world to break the news online, on television and radio.
"It was a massive team effort, involving different broadcast networks, photographers and correspondents working together, and I was proud of what was achieved.
"When they meet again I’ll do my best to bring you the news first once more!"