What is Trinity Carol Roll?

The Trinity Carol Roll is a 15th-century manuscript of thirteen English carols held by the Wren Library at Trinity College, Cambridge. It is the earliest surviving example of polyphonic music written in English. Compiled after 1415, it contains the earliest of two manuscript sources for the Agincourt Carol which tells of Henry V's victory at the Battle of Agincourt, as well as several early Christmas carols. The majority of texts are in Middle English with some of the carols alternating between Latin and Middle English, a common form for carols of the period known as macaronic.