In 2009, 42 fragments of white marble with Cosmatesque decorative inserts were found in the store rooms of the Vatican Museums. Inscriptions on some of these fragments identified their source as the medieval portico of San Giovanni in Laterano, destroyed in 1732. Shortly after the dismantling of the ancient façade, the slabs were reused in the new floor of the Basilica's Portico Sistino. Research conducted on these fragments demonstrated that they were what remained of the frieze on the front of the portico, consisting of an alternation of panels and disks delimited by a band in Cosmatesque work and filled with mosaics, some of which are figurative and with short inscriptions. The fragments were reassembled where possible and restored by the Restoration Laboratories of Marble and Mosaics of the Vatican Museums, while investigations were carried out on the compositional materials from the Diagnostic Laboratory of the Vatican Museums. At the same time, bibliographical and archival research has been carried out which has allowed for a visualisation of the whole scheme.