Saint Peter Enthroned, sometimes attributed to late 13th-century sculptor Arnolfo di Cambio, with some scholars dating it to the fifth century. One foot of the statue is largely worn away by pilgrims kissing it for centuries. The sunken Confessio leading to the Vatican Grottoes (see above) contained a large kneeling statue by Canova of Pope Pius VI, who was captured and mistreated by Napoleon Bonaparte's army. This has now been moved to the back (eastern) end of the grottoes. In the Confessio is the Niche of the Pallium ("Niche of Stoles") which contains a bronze urn, donated by Pope Benedict XIV, to contain white stoles embroidered with black crosses and woven with the wool of lambs blessed on St. Agnes' day. The High Altar is surmounted by Bernini's baldachin. (See above) Set in niches within the four piers supporting the dome are the larger-than-life statues associated with the basilica's primary holy relics: Saint Helena holding the True Cross and the Holy Nails, by Andrea Bolgi; Saint Longinus holding the spear that pierced the side of Jesus, by Bernini (1639); Saint Andrew with the St. Andrew's Cross, by Francois Duquesnoy and Saint Veronica holding her veil with the image of Jesus' face, by Francesco Mochi. North aisle In the first chapel of the north aisle is Michelangelo's Pietà. On the first pier in the right aisle is the monument of Queen Christina of Sweden, who abdicated in 1654 in order to convert to Catholicism. The second chapel, dedicated to Saint Sebastian, contains the statues of popes Pius XI and Pius XII. The space below the altar used to be the resting place of Pope Innocent XI but his remains were moved to the Altar of the Transfiguration on 8 April 2011. This was done to make way for the body of Pope John Paul II. His remains were placed beneath the altar on 2 May 2011. The large chapel on the right aisle is the Chapel of the Blessed Sacrament which contains the tabernacle by Bernini (1664) resembling Bramante's Tempietto at San Pietro in Montorio supported by two kneeling angels and with behind it a painting of the Holy Trinity by Pietro da Cortona. Near the altar of Our Lady of Succour are the monuments of popes Gregory XIII by Camillo Rusconi (1723) and Gregory XIV. At the end of the aisle is an altar containing the relics of Saint Petronilla