Pope Francis will hold an ordinary public consistory on April 20, where the cardinals of the Church are expected to pave the way for the canonization of the Fatima visionaries.

There are five causes of canonization waiting for approval by the cardinals. Most prominent is the cause of Francesco and Jacinto Marto, two of the shepherd children who witnessed the 1917 Marian apparitions at Fatima.

The cardinals' approval at the consistory is the final step in the process leading up to canonization. Pope Francis has already given approval for the causes to move forward. Following the consistory, canonization dates will be set.

It has been widely speculated that Pope Francis will canonize the Fatima visionaries during his trip to Fatima for the 100th anniversary of the Marian apparitions there. That trip will take place May 12-13.

Francisco, 11, and Jacinta, 10, were the youngest non-martyrs to be beatified in the history of the Church.

The brother and sister, who tended to their family's sheep with their cousin Lucia Santo in the fields of Fatima, Portugal, witnessed the apparitions of Mary, now commonly known as Our Lady of Fatima.

During the first apparition, which took place May 13, 1917, Our Lady asked the three children to say the Rosary and to make sacrifices, offering them for the conversion of sinners. The children did, praying often, giving their lunch to beggars and going without food themselves. They offered up their daily crosses and even refrained from drinking water on hot days.

In October 1918, Francisco and Jacinta became seriously ill with the Spanish flu. Our Lady appeared to them and said she would to take them to heaven soon.

Francisco died April 4, 1919. Jacinta died the following year, Feb. 20, 1920.

Pope John Paul II beatified Francisco and Jacinta May 13, 2000, on the 83rd anniversary of the first apparition of Our Lady at Fatima.

The canonization cause for Sister Lucia Santo – the third Fatima visionary – is currently underway. Sr. Lucia lived to the age of 97, much longer than the other two visionaries, and the Vatican is currently examining information about her life that has been collected over the past eight years since her cause was officially opened.

In addition to the Fatima children, other causes of canonization set for approval at next week's consistory are Cristóbal, Antonio, and Juan, young martyrs of Mexico in 1529; Fr. Faustino Míguez, the Spanish priest who founded the Calasanzian Institute of the Daughters of the Divine Shepherdess; Fr. Angelo da Acri, an Italian Capuchin priest who died in October 1739; and Fr. Andrea de Soveral, Fr. Ambrogio Francesco Ferro, Matteo Moreira, and their 27 companions, martyrs of Natal, Brazil in 1645.