The Angelus recalls the moment of the Incarnation, when the angel Gabriel told the Virgin Mary that she was to be the mother of Jesus. Since the days of the early Christians, it has been customary to remember this moment in the life of Virgin Mary. Over the centuries, the tradition developed to pray three Hail Marys. And since the sixteenth century, three sentences were added.
Pope John XXIII began to recite it on Sundays and holiday in St. Peter's Square holidays before each blessing. This marked the beginning of the tradition of praying the Angelus that continues to this day.
The only time of year when the Angelus is not recited is after Holy Week. During Easter, the Angelus is replaced by the Regina Coeli, a prayer that recalls the resurrection of Jesus and continues until the feast of Pentecost.