The Te Deum (/teɪ ˈdeɪəm/ or /tiː ˈdiːəm/,[1][2] Latin: [te ˈde.um]; from its incipit, Te Deum laudamus (Latin for 'Thee, God, we praise')) is a Latin Christian hymn traditionally ascribed to a date before AD 500, but perhaps with antecedents that place it much earlier.[3] It is central to the Ambrosian hymnal, which spread throughout the Latin Church with other parts of the Ambrosian Rite of Milan in the 6th to 8th centuries. It is sometimes known as the Ambrosian Hymn, although authorship by Saint Ambrose is unlikely. The term Te Deum can also refer to a short religious service (of blessing or thanks) that is based upon the hymn.[4]
It continues in use in many contexts by several denominations. In particular it is the core of a short church service of thanksgiving held, often at short notice, to celebrate good news such as a military victory, the signing of a peace treaty, or the birth of a royal child.