The Prince and Princess of Wales made a bold gesture which gave great insight into their relationship, a body language expert has claimed. Prince William and Princess Catherine had a prominent role in welcoming the President of Germany, Frank-Walter Steinmeier and his wife Elke Budenbender at the start of their historic state visit to the UK on Wednesday.

The royal couple performed their customary duty of meeting the couple at Heathrow Airport in the morning, and escorting them by car to a dais on their eight-mile journey to Datchet Road in Windsor’s town centre. After the official welcome in Windsor, the royal party hosted a lavish state banquet in the castle to honour their German guests.

According to a body language expert, William and Catherine exhibited key signals during their joint appearance in the first half of the first day of the state visit.

Body language specialist Judi James claimed that, during the official welcome in Windsor, the future king and queen showed two “very strong” telling signs of the state of their relationship.

She told the Express: “In the stills photos we can see two very strong ‘tells’ from William and Catherine to illustrate the strength of their amusement and good humour.”

The expert explained: “Catherine’s smile entails dimples plus a tongue that has appeared between her teeth to the side of her mouth, which hints at high levels of inner fun.

“William’s laugh here includes edge-to-edge teeth, which also signals how the couple are at the same level of playful enjoyment.”

She added: “William’s intense face-gazing behaviour as he looks at his wife shows just how finely-tuned they are to each other’s non-verbal signals and how strong his enjoyment is to be prompting what looks like a very carefree smile from her.”

The royal couple later dazzled at the glittering state banquet at Windsor Castle, where Catherine wore a new tiara.

In a nod to the King’s guests, the future queen diplomatically opted for Queen Victoria’s Oriental Circlet Tiara, made of diamonds and rubies, which was designed for Victoria by her German-born husband, Prince Albert, in 1853.

Catherine glittered in a periwinkle blue, floor-length sequined gown with an asymmetric neckline and flowing cape shoulder detail by Jenny Packham for the white tie celebration.

She also wore the late Queen’s earrings, the Royal Family Order and the GCVO Sash and Star.

The Prince of Wales wore a white tie and a Windsor tail coat, and the Most Noble Order of the Garter Sash with the Lesser George.

He was also wearing his miniature medals, Order of the Bath and the Golden, Diamond and Platinum Jubilee and Coronation medal, as well as the Chest Orders of the Order of the Garter and Order of the Thistle and the Neck Order of the Order of the Bath.