No. 46. Romanesque Window, St. Alban’s Abbey.
In the early churches of this period the walls of the nave were unbroken except for the upper windows. With the development of vaulting, the space above the aisle vaults and the covering roof was used as a gallery known as the Triforium. This was not lighted from without, and was a distinguishing characteristic of the Romanesque and early Gothic styles.
The introduction of vaulting in the roof of the nave entailed supports for the arch bands or vaulting ribs, which were carried on pilasters or half columns, dividing the interior façade into bays.
No. 48. Construction of intersecting vaults.
Dark Ages
The unsettled condition of Europe, both before and after the final subjugation of the Roman Empire by Charlemagne in 774 A.D., was necessarily detrimental to artistic progress, and the period to the fifteenth century may be truly described as the dark ages as regards the arts and culture in general.