Before the Breviary reform of St Pius X, the Te Deum was titled “the hymn of Ss Ambrose and Augustine”, in reference to the tradition Saints Ambrose and Augustine composed it as if by divine inspiration, immediately after the baptism of the latter at the Easter vigil of 387. (Incidentally, this was one of the extremely rare years on which Easter fell on its terminus post quem non, April 25th.) “Te Deum laudamus!”, exclaimed Ambrose, “Te Dominum confitemur!”, replied Augustine, and so on. For this reason, many illustrated breviaries the Te Deum is decorated with an image of the two bishops together.
|The Te Deum in a Psalter created in the mid-16th century for a canon of the Duomo of Milan. (Bodleian Ms. Canon. Liturg. 275)|
The baptistery of St John “ad Fontes” is seen in the drawing below as the octagonal building between Milan’s two cathedrals. The larger one on the left, dedicated to St Thecla, was also known as the summer church, used from Easter until the 3rd Sunday of October; the smaller one on the right, the winter church, was dedicated to the Virgin Mary, and used from that Sunday until the Easter vigil. St Mary’s also had a baptistery, named for St Stephen the First Martyr, which is not seen here, and of which nothing now remains; this would have been where St Ambrose himself was baptized. The modern Duomo is built over and oriented the same way as St Mary’s, but is very much larger; St Thecla was demolished in the 16th century, but its memory is preserved by the presence of an altar dedicated to her in the cathedral’s left transept, and by the fact that the cathedral parish as a corporate entity is named for her.
(This post is largely the work of our Ambrosian correspondent Nicola de’ Grandi.)