This image is found in the Church of San Carlo ai Catinari in Rome, Italy.
Today, 24 March, is traditionally the Feast of St. Gabriel the Archangel; it was timed to fall the day before the Solemnity of the Annunciation. When the calendar was revised in 1970, his feast was moved to join that of St. Michael the Archangel in September.
St. Gabriel's name means "God is my strength," and he is notable for his appearance in the book of the Prophet Daniel (Chapters 8 & 9), where he appeared to Daniel, and, of course, for the Annunciation to the Blessed Virgin Mary, announcing the Incarnation of Jesus Christ, and his appearance to Zechariah announcing the conception of St. John the Baptist.
It is hard to think of a better arch-type of the messenger of God, and, for that reason, he is patron saint of a host of folks, from Spanish Ambassadors to postal workers and messengers.
For more on this great member of the Angelic host, you might note:
Notable, too, is that until 1752AD, today would have been New Year's Eve in the English speaking world! You might note this article, Boston Globe: March 25? Happy Colonial New Year!
Live well!