The preceding note by Per Jonas Nordhagen does not take into account the documented history of the mosaics of Sta. Maria Maggiore. Little has been published on the restoration history of the mosaics and less on the nature and effect of these repairs.' This response to Nordhagen's criticism of my studies attempts to begin redressing that omission by describing, with all possible brevity, the archival, documentary, illustrative, and other materials which provide the evidence for a restoration history of the fifth-century mosaics.2 I will conclude with some comments directed towards Nordhagen's specific points of criticism. The most recent extensive repairs of the mosaics of the nave and triumphal arch took place between 1929-1931 and 19361940, during the papacy of Pius XI, under the direction of Biagio Biagetti. His overseer, Giorgio Pianigiani, wrote detailed reports on the condition in which he found the panels of the nave and on their repair; these reports are in the archives of the Laboratorio Vaticano per il Restauro delle Opere d'Arte.3 The archives also contain Anderson photographs of the mosaics of the nave and arch upon which Pianigiani made color-keyed notations of prior repairs in mosaic and fresco, which he ascribed to Leo XII, Benedict XIII, and Cardinal Pinelli, and of damage and superficial irregularities.4 Plaster casts of the panels of the nave made in the course of their repair are preserved in the restoration laboratory. The archives do not have written reports on the condition or repair of the triumphal arch.5 Pianigiani found the nave panels in a ruinous condition, particularly those of the left clerestory wall.6 Many were detached from the brick, their edges lost. Pianigiani noted that some panels of the right clerestory had been restored previously in mosaic as well as fresco, while mosaic repairs on the left wall erano pochissimi e quasi tutti piccolissimi. The Joshua cycle, for example, had been repaired with mosaic tesserae, but little attention was paid to matching the colors. Some cubes had been painted gold after having been placed in the plaster bed.7 The aims of the Biagetti-Pianigiani restoration were conservation and artistic integration.8 Pianigiani consolidated the panels of the nave by removal and resetting or, when feasible, by cement injections. The mosaics were cleaned and then patched, ei her with tesserae or in fresco. It is important to note that because of their goal of integrazione artistica, the restorers ried to absorb the style of the remaining fifth-century mosaics and to replace tesserae so that the difference would hardly be oticed. Pianigiani also removed the sixteenth-century frames of the panels, revealing their original champfered shape and mosaic border of red, white, and blue bands. The mosaic of the triumphal arch it is startling to learn was removed in 111 pieces for repair! Pianigiani removed the two sixteenth-century pilasters and reconstructed in mosaic the lateral edges of the arch that had been damaged by the pilasters and the upper reaches of the first zone. Throughout the face of the arch, he patched the mosaic with new tesserae.9 Between 1848 and 1850 initial steps were taken in a campaign to restore the mosaic panels of the nave. The records for this enterprise are kept in Rome in the Archivio di Stato, Archivio del Camerlengato, tit. Iv, pte. ii, busta 187. Scaffolding was erected for the project and the mosaic frieze of the entablature was restored, but the panels were never touched. The scaffolding was dismantled in 1851.10 In 1824, during the pontificate of Leo XII, repairs on the mosaics of the nave, triumphal arch, tribune, and loggia were initiated. The documents for this campaign are also in the Archivio di Stato, Archivio del Camerlengato, tit. Iv, pte. ii, busta 187, No.