While Princess Kate and Prince William have always marked the milestone in private, this year they're on two-day Scottish tour.

Kate Middleton and Prince William have been married since 2011 and share three children. Here's everything to know about their royal relationship.

Lace was a crucial design component of Middleton’s wedding gown. The dress featured lace that was handmade at London’s Royal School of Needlework based at Hampton Court Palace and was appliquéd with individual flowers that were hand cut from the lace. The bodice and skirt were designed from hand-cut English lace and French Chantilly lace.