The basilica, begun in 1469 and sponsored by Paul II, represents the work of various artists that gave itt the appearance that is visible today to the pilgrim. The apses are the work of Giuliano da Maiano, while Baccio Pontelli built the walkways, giving the sanctuary the appearance of a fortress. Giuliano da Sangallo created the dome in Brunelleschi's style and Donato Bramante worked on various modifications and consolidations. The basilica was completed in 1587 with the construction of the façade in late Florence Renaissance style by three architects: Giovanni Boccalini, Giovan Battista Ghioldi and Lattanzio Ventura. It consists of a hemicycle and 13 late Gothic apse chapels of Florentine derivation, called chapels of the nations.
In the dome, decorated with frescoes by Cesare Maccari, we can recognize the cycle of the Litany of Loreto, the Holy Trinity surrounded by the Thrones, Cherubim Dominations, Serafini, Powers, Principalities, the archangels Michele Raffaele and Gabriele and the invocations to Mary as Queen. The bronze doors forged in the Recanati foundry in 1600, representing episodes from the history of salvation, close the exterior of the basilica.
The apostolic palace was designed by Donato Bramante. The works were directed by Sansovino, then by Antonio da Sangallo the Younger and in the sixteenth century by Giovanni Boccalini. It was finished by Luigi Vanvitelli to whom we owe also the elegant bell tower.
(taken from The Holy House of Loreto by Padre Giuseppe Santarelli-translation by Giulia Bogotto)