When did the Marian devotions begin, especially amongst the Roman

These things were apparent from nearly the very beginning. They developed because they were believed by a substantial number of people.

>>1520088
Post-Trent, it was enforced by church hierarchy

Biblical Mariology:
Luke
Galatians and other epistles
Selected passages from John like 19:27
Revelation 12 is intepreted by the Catholic Church as referring to Mary, etc.

Mariology itself + the Second Eve +
Perpetual Virginity:
Iraeneus

Mother of the Church:
Ambrose

Assumption:
Liber Requiei Mariae (apocryphal)
John of Damascus

Mediatrix:
A prayer attributed to Ephrem the Syrian
Basil of Seleucia

Mother of God + Queen of Heaven:
Council of Ephesus

Immaculate Conception:
Gregory Nazianzen

Our Father and Hail Mary recited with prayer beads:
Middle Ages, for example in 13th century Paris four different trade guilds were making prayer beads.

Co-Redemptrix:
Debated in the late Middle Ages between Franciscans (in favor) and Dominicans (against)

>>1520088
The basis was always there even in apostolic times and confirmed by the early great councils.

Mass devotion in a goddess like manner really took off in the 12th century in western Europe. It is contemporary with all the medieval courtesy literature and the overall bizarro worship of women that became common at the time.

The earliest form of it is to be found in the second century, particularly with the whole New Eve reference to Mary and the emergence of the Protoevengelium.

Even the whole Assumption/Dormition tradition regarding Mary is found in the Ante Nicene period though 3rd century in one of the NT apocrypha(non Gnostic). This is the timeframe where the oldest prayer to Mary is dated to.

So in a nutshell, it emerged early though aspects like her sinlessness are contested.