Final answer:
Tribunes in churches like Santiago de Compostela and Saint-Sernin were designed to manage the flow of pilgrims visiting the sacred relics, accommodating more visitors and aiding in the orderly circulation within the church.
Step-by-step explanation:
The purpose of tribunes such as those found at Saint James at Santiago de Compostela and Saint-Sernin Toulouse was to facilitate the circulation of the large number of pilgrims visiting these churches. These tribunes, with their upper galleries overlooking the nave, could accommodate more people and allowed for an organized flow of pilgrims who came to venerate the relics and seek the spiritual benefits of their pilgrimage. The cruciform plan of these churches not only symbolically represented the cross but also efficiently directed the movement of pilgrims from the western portal through the nave, around the ambulatory, and out the transept, ensuring an orderly and reverential visit.