Kate Middleton wore a navy Erdem jacket and skirt combo with a pleated peplum and white flowers, embracing the peplum trend.

She wore Princess Diana's diamond and sapphire double drop earrings and the Prince of Wales plumes brooch as a necklace.

Peplums have slowly been coming back into fashion and have been featured on celebrities such as Florence Pugh, Deepika Padukone, and Mindy Kaling.

Kate previously wore a blue, polka dot Alessandra Rich gown with a peplum detail to the Wimbledon men's finals in August.

Peplums are more elegant than in the 2010s, and at least one celebrity wears them on every red carpet.

This article serves as a warning to prepare for the onslaught of added waist fabric.

Middleton has a reputation for influencing fashion trends with just one look.

Kate is often seen embracing monochrome dressing.

Erdem is one of Kate's go-to brands for royal events.