I read a book on the history of the Rosary a while back and it is actually unclear what Our Lady actually taught to St. Dominic if anything (she may have just encouraged the Marian Psalter which already was practiced at the time):
The first documented mysteries to be associated with the Marian Psalter (150 aves), which went back a lot farther, was in about 1275 and the mysteries were three in number: Annunciation, Nativity, Assumption–that’s it. Additional mysteries then developed–all joyously themed. These mysteries are mostly found in the modern non-sorrowful mysteries, but there were others like the adoration of the Magi or more heavenly Marian ideas, like her being given the role of Illuminatrix, or having her wishes united to Christ’s and answered by Christ (ie her role as Mediatrix), or her eternal joy.
The next development was the addition of the Pater Nosters in the 1400s. I forget the name of the person who spread this, but he suggested meditating on the Passion of Christ on the Paters. This is when roses became more formally associated with the Marian Psalter–he said the prayers were like Roses sent to the Blessed Mother, Aves were white roses and the Paters (with Passion meditations) were red roses. The Sorrowful meditations were pretty much identical to the Sorrowful mysteries now in most versions of the Psalter back then, but one less popular version had more Marian-themed sorrows (similar to the seven Dolors we recognize today). The number of mysteries still varied though. Some had more general themes, rather than specific mysteries (ie “heavenly joys of Mary”), some versions had ten total mysteries, some had sets of seven (not sure how that worked), one had ninteen (I can see how these odd ones didn’t stick as long!), etc…
This was also when the Psalter began to be reduced to only 50 Aves per day in many areas. The Vita Christi Rosary spread by Dominic of Prussia (50 Aves, but with 50 mysteries on the life of Christ; although supposedly he had a 150 mystery version too) became the most popular (more on its origins below). At the time, some condemned this as destroying the Psalter (including Bl. Alan de Rupe, who first related the idea that St. Dominic was taught the Marian Psalter by Our Lady).
This is when Bl. Alan de Rupe wrote his work on the Marian Psalter in order to return to the more authentic version as he saw it. He supported only praying the 150 a day and refused to call it the “Rosary” and forbade others from calling it that too, since he saw what was called the Rosary at the time (the fifty per day) as a corruption of the Psalter. His mysteries had three groups, they were general and not specificly listed except for the last group. His general themes were: Incarnation, Passion, Resurrection (which included the Resurrection, Ascension, Holy Spirit’s descent, Glorification of Christ, Final Judgment).
continued…