The dedication of May as the month of the Blessed Virgin Mary arose among Jesuits in Rome in the late 18th century. In the early years of the 19th century it quickly spread throughout the Western Church, and, by the time of Pope Pius IX's declaration of the dogma of the Immaculate Conception in 1854, it had become universal.

The Most Holy Rosary of the Blessed Virgin Mary

In the Western Church, the rosary is the preeminent form of prayer to the Blessed Virgin Mary. May is a very good month to begin praying the rosary daily.

The Holy Father's Intentions for the Month of May 2018

Evangelization: The Mission of the Laity  - That the lay faithful may fulfill their specific mission, by responding with creativity to the challenges that face the world today. 

Feasts for May

The feasts on the General Roman Calendar celebrated during the month of May are:
May 1 - Joseph the Worker, Optional Memorial
May 2 - Athanasius, Memorial
May 3 - Philip and James, Feast
May 5 - First Saturday Devotion to the Immaculate Heart of the Blessed Virgin Mary
May 6 - Sixth Sunday of Easter, Sunday
May 10 - Ascension of Our Lord; Damien de Veuster, priest; John of Avila (some places), Optional Memorial
May 12 - Nereus and Achilleus; Pancras, martyrs, Optional Memorial
May 13 - Ascension or the Seventh Sunday of Easter, Solemnity
May 14 - Matthias, Feast
May 15 - Isidore the Farmer (USA), Optional Memorial
May 18 - John I, Optional Memorial
May 20 - Pentecost; Whitsunday, Solemnity
May 21 - Mary, Mother of the Church; Christopher Magallanes and companions; Eugene de Mazenod (Canada), Optional Memorial|
May 22 - Rita of Cascia, Optional Memorial
May 25 - Optional Memorial of St. Bede the Venerable, priest and doctor; St. Gregory VII, pope; St. Mary Magdalene de Pazzi, virgin, Optional Memorial
May 26 - Philip Neri, Memorial
May 27 - Trinity Sunday, Solemnity
May 31 - Visitation of the Blessed Virgin Mary, Feast