Today, the Church celebrates the Annunciation of the Blessed Virgin Mary, when the angel Gabriel announced to Mary that she would bear a son. During Mass today, Pope Francis consecrated all of humanity, including Russia and Ukraine, to the Immaculate Heart of Mary, calling it a spiritual act of trust. He also spoke about how God chose Mary to change history and begin a new story of peace and salvation. The Annunciation is a popular theme in Christian art, with depictions dating back to the 4th century CE. Read more about the symbolism in these depictions here.