Sampietrini is the pavement found in the historic district of Rome and in St. Peter's Square, Vatican City. The earliest examples were made by trimming large blocks that had been used in ancient Roman roads, as recently discovered in fifteenth- and sixteenth-century archeological excavations. The first documented use in Rome of "sampietrini" stones was during the reign of Pope Pius V (1566–72). Over the next two centuries, the stones were used to pave all the main streets of Rome, because this mode was superior to brick, as it provided a smoother, stronger surface for carriages.