The Commonwealth Day Service, held at London's Westminster Abbey on the second Monday of March, is attended by members of the British royal family, led, of course, by Queen Elizabeth II. Over the years, the royal VIP list at the multi-faith church service, which recognizes the 53 countries and its people that make up the Commonwealth, has varied, but often includes Prince Charles and Camilla, the Duchess of Cornwall, Sophie Wessex and often, in recent years, Prince William and Kate Middleton. The Duchess of Cambridge's style for the formal church occasion is always picture perfect, from her designer hats to her heels. Take a look back at the style details from her Commonwealth outfits both past and present.2018On March 12, 2018, pregnant Duchess Kate was elegant in a navy blue coat and dress by luxury label Beulah London as she arrived at Westminster Abbey with Prince William, Prince Harry and Harry's fiancée Meghan Markle.Photo: Getty Images
The Duchess accessorized her ensemble with sparkling earrings and a brooch, and a wide-brimmed navy blue hat by Lock and Co.Photo: Getty Images
Kate completed the look with a a Jimmy Choo Celeste clutch and blue suede shoes that were nearly identical to those of her future sister-in-law Meghan Markle, far left.Photo: Getty Images
2016The Duke and Duchess of Cambridge showed their support for the Queen as they arrived at the annual Commonwealth service at Westminster Abbey on March 13, 2016. That year, William and Kate were joined by other members of the royal family, including Prince Philip, Prince Andrew and Prince Harry.Wearing a grey lace embellished Erdem coat, Kate looked impeccably smart as she arrived with her husband. The couple had left their children Prince George and Princess Charlotte at home while they carried out the engagement.Photo: Getty Images
Kate accessorized the late winter outfit with a grey John Boyd hat, drop earrings and a suede clutch in a matching hue.Photo: Getty Images
Underneath the John Boyd hat, Duchess Kate wore her hair in full, loose curls that cascaded down her back.Photo: Getty Images
2015On March 8, 2015, crowds eagerly waited outside Westminster Abbey for a glimpse of the Duchess of Cambridge, then pregnant with daughter Princess Charlotte, as she carried out one of her final engagements before her due date. Joined by Prince William, the Duchess wrapped up in a pale pink Alexander McQueen coat which she had previously worn at Trooping the Colour in 2013, one of her final engagements before the birth of Prince George.Photo: Getty Images
The Alexander McQueen coat's tone and pearl buttons were perfectly accessorized with a soft rose box clutch.Photo: Getty Images
Duchess Kate wore her her hair in a half updo, not unlike the style she wore for her 2011 wedding day with Prince William. The finishing touch of the outfit was a pretty Jane Taylor hat. Photo: Getty Images