Kate Middleton looked radiant in an emerald green gown as she joined her husband, Prince William, at King Charles’ private 75th birthday party last night. The party was held at Windsor Castle and was attended by a close circle of family and friends.

Kate’s gown was custom-made by Jenny Packham and featured a fitted bodice, flowing skirt, and delicate beading. She accessorised with her emerald green earrings and necklace from Van Cleef & Arpels.

Earlier in the day, 41-year-old Prince William and Princess Kate sent a heartfelt birthday message to King Charles on social media, complete with pictures of their families.

On Wednesday, Kate convened a global gathering of specialists at the Design Museum in central London, which was organised by her Royal Foundation Centre for Early Childhood.

“It is time we understood that building a healthier world means nurturing the foundations that support our children — everything from the systems that govern early care through to our attitudes to those raising the next generation, and the support they receive,” Kate said at the event.

A significant royal responsibility that King Charles carried out on his birthday was the Coronation Food Project’s launch.

Touring the South Oxfordshire Food and Education Alliance, the 76-year-old King and Queen Camilla saw firsthand how the new initiative will “bridge the gap between food waste and food needs across all four nations of the United Kingdom, helping people and helping the planet,” according to the palace.