The Ambrosian hymns are a collection of early hymns of the Latin liturgical rites, whose core of four hymns were by Ambrose of Milan in the 4th century. The hymns of this core were enriched with another eleven to form the Old Hymnal, which spread from the Ambrosian Rite of Milan throughout Lombard Italy, Visigothic Spain, Anglo-Saxon England and the Frankish Empire during the early medieval period (6th to 8th centuries); in this context, therefore, the term “Ambrosian” does not imply authorship by Ambrose himself, to whom only four hymns are attributed with certainty, but includes all Latin hymns composed in the style of the Old Hymnal. The Frankish Hymnal, and to a lesser extent the “Mozarabic (Spanish) Hymnal” represent a reorganisation of the Old Hymnal undertaken in the 8th century. In the 9th century, the Frankish Hymnal was in turn re-organised and expanded, resulting in the high medieval New Hymnal of the Benedictine order, which spread rapidly throughout Europe in the 10th century, containing on the order of 150 hymns in total. Origin The earliest Latin hymns were built on the template of the hymns (ῠ̔́μνοι) of the Greek and Syriac churches of the second to third centuries. The first Latin hymns were composed by Hilary of Poitiers (d. 367), who had spent in Asia Minor some years of exile from his see, and had thus become acquainted with the hymns of the Eastern Church; his Liber Hymnorum has not survived. Hilary, who is mentioned by Isidore of Seville as the first to compose Latin hymns, and Ambrose (d. 397), styled by Dreves (1893) “the Father of Church-song”, are linked together as pioneers of Western hymnody. The Old Hymnal consists of the extant Latin hymns composed during the 4th and 5th centuries. The hymns of the Old Hymnal are in a severe style, clothing Christian ideas in classical phraseology, and yet appealing to popular tastes. At the core of these is the hymn Te Deum. Since the spread of the Old Hymnal is closely associated with the Ambrosian Rite, Te Deum had long been known as “the Ambrosian Hymn”. While it certainly dates to the 4th century, Ambrose's authorship is no longer taken for granted, the hymn being variously ascribed to Hilary, Augustine of Hippo, or Nicetas of Remesiana. Isidore, who died in 636, testifies to the spread of the custom from Milan throughout the whole of the West,