The concern to find means to make evident that which is not evident can be considered one of the historical constants of human thought. In pursuit of this aspiration, man has always striven to reach the unperceivable by means of what is manifest, and in this way he has come to elaborate complex systems of signs whose primary purpose is the communication of ideas and feelings.

Antonio de Alloytiz was the most outstanding architect of the altarpiece during the 17th century in Vizcaya, to which his knowledge of the sculptural style of Gregorio Fernández and his contacts with the altarpiece architect Pedro de la Torre contributed. We study his relationship with Torre and other court architects such as Bernabé Cordero and the Jesuit Francisco Bautista, his numerous trips to the court, where his business dealings led him to buy and sell a chapel in the convent of Santo Domingo el Real, acting as an intermediary in the context of a complex lawsuit. We also attribute to him two works conserved in museums and related to Madrid for different reasons, a monstrance from the Diocesan Museum of Sacred Art in Bilbao, which belonged to the disappeared main altarpiece of the parish church of Ochandiano, and an Immaculate Conception in the National Archaeological Museum, possibly from an altar in the church of Gordejuela.

The aim of this study is to research and analyse the 15th-century panel paintings in the National Archaeological Museum, whose artists’ names are well known. These works reveal the stylistic evolution of the Spanish schools, in which the Italo-Gothic, International and Flemish artistic currents are represented.