The prayers in Latin
I am including these prayers to help educate readers about the beliefs and mindsets of the medieval/early modern world.

Pater noster, qui es in caelis, sanctificetur nomen tuum. Adveniat regnum tuum. Fiat voluntas tua, sicut in caelo et in terra. Panem nostrum quotidianum da nobis hodie, et dimitte nobis debita nostra sicut et nos dimittimus debitoribus nostris. Et ne nos inducas in tentationem, sed libera nos a malo. amen.
The most important prayer for medieval Catholics to be able to recite by heart (yes, in latin). An inablility to recite this prayer correctly could be used as proof of a charge of witchcraft! Our father, who art in heaven, hallowed be thy name. Thy kingdom come, thy will be done, on earth as it is in heaven. Give us this day our daily bread, and forgive us our tresspasses, as we forgive those who trespass against us. And lead us not into temptation, but deliver us from evil. (amen)

Ave Maria, gratia plena. Dominus tecum. Benedicta tu in mulieribus, et benedictus fructus ventris tui, Iesus. Sancta Maria, Mater Dei, ora pro nobis pecatoribus nunc et in hora mortis nostrae. amen.
The Ave is another of the prayers medieval western Christians were expected to know by heart. Because of the belief in the communion of saints (the dead are only physically dead, but their souls are living), Mary (or any other saint existing outside of linear time with God) could hear the prayers of the living. It was thought that Mary loved hearing the Ave prayer because it reminded her of her happiness at the Incarnation.. Hail Mary, full of grace, the lord is with you. Blessed are you among women, and blessed is the fruit of your womb, Jesus. Holy Mary, mother of God, pray for us sinners, now and in the hour of our death.

Credo in Deum Patrem omnipotentem, Creatorem caeli et terrae. Et in Iesum Christum, Filium eius unicum, Dominum nostrum, qui conceptus est de Spiritu Sancto, natus ex Maria Virgine, passus sub Pontio Pilato, crucifixus, mortuus, et sepultus, descendit ad inferos, tertia die resurrexit a mortuis, ascendit ad caelos, sedet ad dexteram Dei Patris omnipotentis, inde venturus est iudicare vivos et mortuos. Credo in Spiritum Sanctum, sanctam Ecclesiam catholicam, sanctorum communionem, remissionem peccatorum, carnis resurrectionem, vitam aeternam. amen.

This Credo is also known as the Apostles Creed, and is the Catholic statement of beliefs. Not a part of all early Rosary meditation/prayer cycles, including the Credo became more commonly included as the 16th C went on. However, I am unsure if this form was used, or the longer Nicene Creed (see below.) The Nicene Creed is the more accurate--and longer--statement of beliefs, and contains one element that the Orthodox Churches could not accept (regarding the Holy Spirit proceeding from both the Father and the Son). . I believe in God, the Father Almighty, Creator of heaven and earth; and in Jesus Christ, His only Son, our Lord; Who was conceived of the Holy Spirit, born of the Virgin Mary, suffered under Pontius Pilate, was crucified, died, and was buried. He descended into hell; the third day He arose again from the dead; He ascended into heaven and sits at the right hand of God, the Father Almighty: from thence He shall come to judge the living and the dead. I believe in the Holy Spirit, the holy Catholic Church, the communion of saints, the forgiveness of sins, the resurrection of the body, and life everlasting.

Credo in unum deum, Patrem omnipotentem, factorem caeli et terrae, visibilium omnium et invisibilium. Et in unum Dominum Iesum Christum, Filium Dei unigenitum, et ex Patre natum ante omnia saecula. Deum de Deo, Lumen de Lumine, Deum verum de Deo vero, genitum non factum, consubstantialem Patri, per quem omnia facta sunt. Qui propter nos homines et propter nostram salutem descendit de caelis. Et incarnatus est de Spiritu Sancto ex Maria Virgine, et homo factus est. Crucifixus etiam sub Pontio Pilato, passus et sepultus est, et resurrexit tertia die, secundum Scripturas, et ascendit in caelum, sedet ad dexteram Patris. Et iterum venturus est cum gloria, iudicare vivos et mortuos, cuius regni non erit finis. Et in Spiritum Sanctum, Dominum et vivificantem, qui ex Patre Filioque procedit. Qui cum Patre et Filio simul adoratur et conglorificatur. Qui locutus est per prophetas. Et unam, sanctam, catholicam et apostolicam Ecclesiam. Confiteor unum baptisma in remissionem peccatorum. Et expecto resurrectionem mortuorum, et vitam venturi saeculi. amen.

I believe in one God, the father, the almighty, maker of heaven and earth, of all that is seen and unseen. And in one Lord, Jesus Christ, only begotton son of God, born of the Father before all ages. God from God, Light from Light, True God from True God, begotton, not made, one in being with the Father, through whom all things were made. For us men and for our salvation he came down from heaven. By the power of the Holy Spirit, He was born of the Virgin Mary and became man, For our sake he was crucified under Pontius Pilate, suffered, died and was buried. On the 3rd day He rose again in fullfillment of the Scriptures. He ascended into heaven, and is seated at the right hand of the Father. He will come again in glory to judge the living and the dead, and his kingdom will have no end. I also believe in the Holy Spitit, the Lord, the giver of life, who proceeds from the Father and the Son. With the Father and the Son he is worshipped and glorified. He has spoken through the prophets. I believe in one holy, catholic and apostolic church. I confess one baptism for the forgiveness of sins. And I look for the resurrection of the dead, and the life of the ages to come. amen.