The Duchess of Cambridge had all eyes on her elegant ensemble as she stepped into St Paul's cathedral on Friday morning (June 10). Kate was the epitome of chic wearing a pale-blue creation by one of her favourite designers, Catherine Walker.
The dress featured white appliquéd lace detailing running the length of the dress, while a V neck added a modern touch to the formal number.
Kate topped off the look with a white pillbox hat by her favourite milliner Jane Taylor. Her famous locks were tied up into a chic chignon that ensured the stunning headgear took centre stage.
The royal has long been a fan of Catherine Walker, often sporting her designs for formal events.
Kate was accompanied by her husband Prince William as she arrived at the cathedral, and they joined a host of other royal family members to celebrate the Queen's 90th birthday.
Prince Charles, the Duchess of Cornwall and Prince Harry were all in attendance, while Prince Andrew and his daughters Princess Eugenie and Princess Beatrice also made up the royal party.
The service is held each year to mark the Queen's birthday and falls on the day before the traditional Trooping the Colour ceremony.
The service was held to celebrate the Queen's life with a series of prayers, hymns, readings and musical performances. It marks the beginning of a weekend of national and Commonwealth celebrations.
Prominent guests at the ceremony included Prime Minister David Cameron, who gave a reading from the New Testament, and the Archbishop of Canterbury, who preached the sermon.