Where Does the Rosary Come From?

Jesus gave us the prayer we often call "the Our Father". But where do the other prayers of the Holy Rosary come from, like the Hail Mary? The Glory Be? Who selected the mysteries that we meditate on for each decade? ...who even decided to pray a rosary in "decades"?

Fr. Mike breaks down the historical origins of the rosary as well as the logic that the saints who went before us used to organize the rosary as we know it today.