The six celebrated masses based on the L’Homme armé melody and preserved in a fifteenth-century manuscript now found in Naples (Bibl. Naz. MS VI.E.40) rest on an immense scaffold of text and melody and, as we will see, on a well-defined liturgical and typological framework. A fresh look at these pieces, drawing on books of liturgy, spirituality, and art made for Dukes Philip the Good and Charles the Bold of Burgundy, provides a deeper understanding of these works. The heretofore unnoticed source for the texts of the Kyrie tropes in Masses I and VI is the famous trope Cunctipotens genitor, which enjoyed the highest rank in the Burgundian ritual. The tropes for the remaining Kyries II-V form a didactic, liturgically focused series based on typological treatises found in the ducal library, and they suggest analogous ways of approaching other L’Homme armé masses with added texts, such as those by Regis and Tinctoris. Together, the six Burgundian masses were likely used as needed for Sundays across the year. The musical treatment of snippets of the L’Homme armé melody in each mass tenor is analogous to procedures seen in other sacred treatises produced for the court. Recognizing these features in the masses helps situate them in the Burgundian milieu and offers new insight into the ubiquitous theme of the Armed Man in music.