They're not the first family to use hand-me-downs - but they are one of the most high-profile.
Duchess of Cambridge Kate wore her blue mother's dress today (complete with stain) on Monday as she gave her first public speech.
The 'Trina' dress from high street chain Reiss, was first worn by her mother Carole Middleton to Ascot in 2010.
Kate's not the first member of Britain's most famous family to recycle. Last week Camilla wore a brooch which used to belong to the late Princess Diana and Kate has form, raiding her mother's wardrobe last year.
The Duchess wore a £650 Collette Dinnigan design to a friend's wedding which had first been worn by her mother in 2009.
Princess Anne, meanwhile, was spotted wearing a dress from the 1981 wedding of Charles and Diana 27 years later.
See below for pictures and a video of Kate in her speaking engagement today.