"In my first account, Theophilus..."

Thus begins the Acts of the Apostles. The "first account" to which the writer refers is the Gospel according to Saint Luke, whose feast day is today on both the traditional and reformed Roman calendar.

Luke was a convert to the faith in (obviously) the early Church, and was a companion to St Paul, who refers to him as "the beloved physician" (Colossians 4:14). In addition, he was said to be an artist, and according to legend, painted the first portrait of the Blessed Mother. The manner of his death is not entirely clear, although tradition assigns him the crown of martyrdom, and he is remembered as such by the priest's wearing of red vestments for this day. He is traditionally symbolized by the ox, one of the four winged creatures in the Apocalypse, along with the man (Matthew), the lion (Mark), and the eagle (John).

Luke is also the patron saint of artists, physicians, and (I'm not sure about this but I wouldn't be surprised), oxen.