The study of two previously untranscribed documents relating to the altar of the church of Madonna di Galliera, one of the most prestigious Renaissance works in Bologna, gives us an insight into the antiquarian climate behind the project. The people involved, Bartolomeo and Ludovico Ghisilardi, Giovanni Beroaldo, Achille Bocchi, Alessandro Manzuoli and Sebastiano Serlio, the architect of the undertaking, all appear to have had connections with the local Accademia del Viridario, the scholarly institution of studies on Vitruvius, whose members included some of the Bolognese clients of Baldassarre Peruzzi. The relations of the Florentine sculptor Niccolò Tribolo with Peruzzi, whom he had known since the 1520s in Rome and for whom he had worked on the tomb of Adrian VI (Santa Maria dell'Anima), his descendence from Jacopo Sansovino, and his proximity to Giovanni Gaddi, cleric of the Apostolic Camera and one of the leading supporters of the Roman Società della Virtù, the focal point of interest in Vitruvius, are elements that help us to understand the reasons for his involvement in the main part of the sculptural decoration of the altar, the great marble altarpiece with the Assumption of the Virgin and the Apostles (1537-1538). It is difficult to establish whether the choice of calling him back to Bologna was attributable to Serlio, or associated with the interest of Alessandro Manzuoli, one of the greatest experts on Vitruvius, a friend of Gaddi and frequenter of Roman antiquarian meetings. What appears to be certain is that Tribolo – who had worked on the sculptures of the side doors of the Basilica di San Petronio during his first stay in Bologna in 1525-1527 – had come to the city thanks to the canon Bartolomeo Barbazza, an ancestor of Alessandro Manzuoli, and had probably enjoyed the protection of Serlio himself. With the aid of various documents (1534-1540), the paper examines the events associated with the destroyed Galliera altar, from the initial employment of Lombardian craftsmen, up to the contributions of Giacomo Fantoni, and Teodosio Brocchi. The models of its perspective structure are traced and Pordenone is identified as a possible source of the compositional scheme adopted by Tribolo, who had just returned from a period of time spent in Venice.