A Latin inscription on the middle crossbar produced after Bernward's death[2] gives the year 1015 as the terminus ante quem for the creation of the doors:
The raw material for the casting was Gunmetal, which consisted predominantly of copper (above 80%) with roughly equal parts of lead, tin, and zinc.
Even the doorknockers in the form of grotesque lion's heads with rings of grace in their mouths were included in the original mold rather than being soldered on later.
The left door depicts the increasing estrangement of humanity from God from top to bottom: the Creation, the Fall, Cain's murder of Abel.
In some cases, several events which chronologically occur one after another are depicted in a single panel, leading to an odd sense of multiplicity.
[11] Moreover, the impact of the frames is significantly reduced in favour of the figural scenes by their narrowness and the flat relief, so that they appear like the images of a contemporary illustrated manuscript, like the Codex Aureus of Echternach.
Especially relevant in this respect is the figure of Cain who looks up to the Hand of God in heaven with fearful, terror-stricken eyes and pulls his cloak tight around his body.
[15] Unlike, for example, the Market Portal of the Mainz Cathedral, the identity of the artist responsible for the Bernward Doors is not preserved.
As a result, older research attempted to identify a varying number of different artists on the basis of stylistic analysis of the individual panels.
[20] As his biographer Thangmar reported in the Vita Bernwardi, Bishop Bernward lived first in the Hostel of the Schola Francorum at the Vatican and then in the Imperial Palace on the Palatine during his stay at Rome in 1001/2.
[21] He probably also saw the Late Antique wooden doors of Santa Sabina with their relief cycle in which Old and New Testament scenes are arranged opposite each other in a typology.
[23] Franz Dibelius first pointed out the clear parallels between illumination of manuscripts in the time of Charles the Bald and the composition of the images and figures of the left door.
[25] Rudolf Wesenberg drew further iconographic and stylistic connections, but with traditional frescos in St. Paul beyond the Walls and Old St. Peter's which Bernward could have seen while in Rome.
But the installation of the doors on the south aisle has also come into question, since foundation remains of a narthex were found there, next to the western stairway tower.
If the doors were located in the western part of the building, they would have had to have been moved pretty soon after, since the cathedral was drastically altered by his successors Gotthard, Azelin and Hezilo.
"[41] The rite of the expulsion of the penitents in Lent derives its meaning from the banishment of Adam and Eve from Paradise shown on the doors.
"The images of the left leaf with the creation of humanity, the fall of man and the story of Cain and Abel corresponds to the breviary reading (Genesis 1-5.5) on Septuagesima Sunday and the following week, which begins the pre-Lenten period.
"[42] Thus in its original location, the door probably also served for the education of the penitents, who were restricted to the vestibule (Narthex or "Paradise") of the churchbuilding during Lent.