The Cambridge Lover's Knot Tiara Kate also borrowed a piece from the queen for the annual diplomatic reception at Buckingham Palace in December 2015. For it she selected the Cambridge Lover's Knot tiara, which was a wedding present from the queen to Princess Diana. The tiara had previously been owned by Queen Mary and features 19 diamond arches, each hung with a pearl suspended from a diamond lover's knot bow. Image Source: Getty / Max Mumby/Indigo